I literally used to think packing was just taking everything off its hangers from my wardrobe and putting it all into a suitcase to make sure I have CHOICE? This is absolutely not a option when travelling. Me and Joe have shared a suitcase as we are travelling throughout 3 months from Italy at like 28 degrees to Sofia at -5 degrees. I do miss my beautiful array of clothes but the less things you take mean that you can buy things that you fall in love with on the way, my absolute favourite item I have bought is my pink fluffy coat!  
Toiletries!

 Have a bag full of necessities such as tablets which are only like 30p from home. I ended up paying £4.82 for ibuprofen while travelling because I ran out. Shampoo and conditioner etc you can get along the way from pretty much anywhere. If you are travelling from place to place try to make things such as shampoo last until you leave to travel to your next destination. There’s nothing worse than having to buy new products and then leave almost full bottles behind because you can’t take them with you. (Due to luggage requirements) 

Plenty of socks and pants!

Its likely when your travelling you won’t always be accessible to a washing machine or have time to go to the launderette, you will want to make sure you have plentyyyy of undies and socks and I mean plenty! They’re always able to squeeze into whatever luggage you’re taking so the more the merrier!

Comfy shoes

I’ve been living in my slip on vans as you may of read they are a lot more useful than the dressy heeled shoes I packed (useless for walking in snow). Pack a versatile pair of shoes that you won’t mind wearing day in day out. My vans are comfy and have scotch guard material so will last a long time! You don’t want to take a pair of trainers or shoes that are on their last legs and end up buying a pair while you’re away. And plus like Joe said it’s pretty cool to keep the pair of shoes you travelled in because you can remember all the countries they’ve walked on! 
Plenty of clothes for all weather

Taking layers of different clothes is the best idea as you can layer up or down in different weather climates. This is so much better than having huge jumpers that take up your whole bag. Pack crop tops, long sleeve tops, thin jumpers, jacket which is waterproof this is useful for millions of destinations. Also it gives you more options if you aren’t able to wash it all regularly. 

Plug adapters 

You will need plug adapters this seems obvious but make sure you have it on your list as they are a lot more expensive to buy in the visiting country than before hand. You can also buy multi use ones if you are travelling to all different countries.
Camera or phone

Obviously you will want to capture the memories of your travels you may even want to take a sim only phone if your planning on staying in a specific country for a long time and just buying the local sim. However Joe has got a sim only pay as you go sim (the network 3) which charges you the same rate in a list of specific countries, this has been very helpful. 
Debit card

Our debit card we have used has been so useful when travelling we are able to top it up on our phone from our bank account. Look into the credit card that gives you the best rate. We have been able to use it in every country withdrawing cash and topping up without an interest rate. We top up the card from our app in GDP and it automatically changes the currency when you use it in any country. This is so good because you don’t need to keep transferring money into different currencies and can use it just like a normal bank card. You also get the best bank exchange rate at the time of using your card. (Revolut bank) 
Copies of your important documents

Ensure to make copies of important documents in case of loosing them. Such as a photocopy of your passports, this ensures that if you are ever stuck in the unfortunate situation of losing it, you still have a copy.