Here are the 10 things you should NEVER take on vacation.

The wisdom in packing isn’t knowing what to take, but what to leave out; so I thought I’d bring you a round-up of some things nobody should take on holiday, business trips, vacay or extended travel.

1. Plants:

I had a Great Aunt (may she rest in peace) on the Irish side of my family who used to travel to Ireland every year. Every year, so I heard, she’d get a flowering plant to bring back and put in her garden. Not only is this highly illegal and awkward to actually transport (she’d always hide them in her handbag), but it’s also an environmental nightmare.

There’s a reason that you shouldn’t take plants on holiday or bring them home – they can take over the local plants and interfere with plant succession in any environment that isn’t their natural one. Cute exotic pets are illegal to take on holiday (e.g. you can’t take your pet rabbit to Queensland, Australia, and you can’t legally take grey squirrels into the UK either) or bring home, too. The technical term is invasive species.

Examples of how this has gone wrong include: Russian Vine in the UK, Pampas Grass in New Zealand and the U.S. and Japanese Kudzu that has invaded parts of the U.S. For these same reasons you should never take plants with you either.

2. Anything with a spray or pump nozzle and no lid:

Even if it has a twist off mechanism, it’s like having a loaded gun of mess ready to go off and wreck the rest of your stuff. Even lids aren’t a guarantee of safety: I once had a great foundation from L’Oreal, and it had a pump top and the flimsiest lid. I kept it in my handbag.

At least, I did until the lid cracked, came off and the pump lid was left squidging 18-hour foundation all over my stuff, a lot of which had to be binned because it was super greasy. It. Never. Came. Off. It also wrecked the bag that it happened in.

The saddest part was that it was a really great foundation and there wasn’t much left by the time I discovered what was happening.  Another time, I ran into the hallway responding to a hissing noise. Certain it was a snake, I gingerly opened my bag with a stick and was met with a puff of body spray.

The sprayer had jammed on something during some subsidence (I carry a lot of crap) and had filled my bag with a floral scent that was at once greasy AND powdery. Again, things had to be thrown away (and it was almost empty when I found it so I had to buy more, which always lives in my bathroom now).

3. Interesting Stones or Pebbles:

I love finding pretty or interesting looking rocks and taking them home. I pocket far less of them than I’d like to, but they always cause the same problems: Rocks are naturally heavy and messy, usually either with mud or sand caked around them and sometimes damp (and isn’t it annoying when you find a stunning one on the beach just for it to fade to a boring off-grey colour when it dries out back home).

I’m not saying don’t pick them up, because I personally can’t help myself particularly if they’re those sparkly ones around the water systems of North Scotland. Just… be sensible. Sometimes, it’s better to take home one medium size rock than twenty little ones. And always take them out of your pockets before you wash your clothes, or remove them from your bag before you do yourself a back injury from the extra weight.

4. Travel mugs:

I’m in two minds about them – on one hand, they’re great if you’re the sort of “urban warrior” who walks along a flat pavement to the underground then sits on a flat train to the office then waits in an elevator until you reach your desk. Travel mugs are probably perfect for these people.

On the other hand, if you’re running for trains, bending down to greet children, getting jostled in busy market places or even driving around a corner with the mug in a cupholder; travel mugs are really useless. They’re not really made for actual travel, they should perhaps be called “transit mugs” instead.

They spill, they leak and they never seem to taste right when you drink from them. Get a very small Thermos instead; I don’t think they’d even spill if you were skydiving or scuba diving.

5. Big pallettes of make-up

They seem like such a great idea. Lots of variety and they save space on taking each different item individually, right? Right until you drop your bag or it gets roughly handled at an airport or someone steps on it and you hear that awful crunching sound.

Additionally, they never come with key pieces such as primer, and you need to budget even more space for brushes. Palettes are best kept at home. Take a capsule set of make-up and keep it in a water resistant bag.

6. Excessive on-location storage solutions:

An English teacher once told me a story about how he’d taken a class of kids to Russia just after the Berlin Wall had come down (if you don’t know why that was big news, read some world history). The country didn’t really have the infrastructure to cope with tourists, and weren’t sure what to make of a school trip. It was 1990, and everyone was still holding their breath, waiting to see if Russia and America were finished trying to destroy each other.

When one pupil’s bag went through the X-Ray machine with a huge tangle of metal wires in the bottom, security officials leapt into action. They surrounded the fourteen year old whose bag it was, pointing AK47s at him and pinning him to the ground. Nobody knew what was happening or why. When the bag was searched, it turned out to be half-filled with wire coathangers.

The boy had never been abroad before and took a bunch of hangers with him. He (and the teacher) then spent seven hours explaining to Russian officials why this had been allowed to happen. Moral of the story? Don’t take storage on holiday. Mary Poppins or not, nobody in the 2010s needs to take their favourite hat stand

7. A bag that’s heavier than its contents:

There are some amazing bags on the market. They have all sorts of bells and whistles – walking pole attachments, aluminium frames, retractable wheels, extra padded compartments, iPod attachment, the list of features are endless. So is their carrying weight. Above all, the most important consideration for a good travel bag are that it fits your stuff in and it’s light enough that you don’t dread moving on.

Amazon lets you check the weight of most products before you buy them – use this feature wisely, and don’t always rely on bag reviews done by well known outdoors journalists who can carry twice their own weight and live off creatine. Unless you do, too, in which case I recommend the lead-lined bombproof suitcase. In lime green, so you never lose it at the airport. It has an ipod attachment.

8. Anything you’d be embarrassed to explain to an old lady or a toddler:

It’s an acid test. Sometimes, in customs, when they see something peculiar in your luggage, they will pull it out and question you on its use and function. If you’d be embarrassed to explain this to your grandma or to a small child, think how much more embarrassing it would be to explain it to a security guard with a crowd of passengers waiting behind you. If the idea makes you blanch, leave it out.

9. Open packets of food:

They spill, they smell, they make a mess, they attract unwanted attention and sometimes they make annoying noises at inopportune moments. Clip it closed with a food clip and put it out of the way until you can finish nibbling.

10. Board games:

A pack of cards is great. Travel scrabble spells fun on the road. Monopoly, Carcassonne, Settlers of Catan and Hero Quest are best left at home. Or someone else’s home.

When someone I know once came to stay with me in Edinburgh, they brought a huge rucksack stuffed full of things. I thought they must be going somewhere else afterwards. Nope. They’d filled their bag with one change of clothes, and topped it up with board games. I’m not sure they even brought a toothbrush.

It was a highly entertaining two days, but we didn’t even play half of the games and the weight of the bag was unbelievable. Also, you’re liable to ruin your boardgames if they’re with you when you capsize in the Amazon.