Mobile phones - for the first 30 days of EU travel most phone network suppliers will not charge you any extra than your normal rate. However after that time, your calls will go via the local network who will charge your network, who will pass those charges onto you. So, you will pay twice! Buy an unlocked in sim free phone (£30 roughly) and buy sims as you travel. Its a cheaper option, however it is less sophisticated than you will be used to.
Tablet/laptop - similar to mobile phone charges costs can rocket so, remove the sim (stick it onto the back of the device so you don`t lose it using a sticking plaster - no glue where the dressing bit is). Then access the internet using your hotel wi-fi or internet cafe. Encourage friends to e mail rather than calling you.
Important documents - scan or photograph all your documents (passports, visas, vaccination certificates, driving licenses etc) and send them to yourself on an e mail. That way if you were to lose everything you have with you, you can still get access to them.
Interail - bargain rail fares which include some Ferries across Europe. Be warned however, if you want to buy another ticket it can take up to ten working days to be delivered and someone has to sign for it. So, it could mean liasing with a future destinations hotel, and factoring this in on your trip. Also, look at your planned route. Check how much it will cost to travel without interail. Example - our travel from Budapest to Keszthely is only about £10 each. Our interail tickets will have run out, but its not worth renewing them until we know where/what we are doing after Keszthely.
Travel light - you honestly don`t need all that stuff! Wash your clothes when you shower each day, they will dry quickly enough in the summer months. Then replace when they get too grotty. We plan to do a launderette wash every so often.
Bags - we used dragbags rather than rucksacks as we found them more comfortable and practical. Remember to buy waterproof covers as most bags (including rucksacks) are not waterproof.
Food - The local supermarket is your friend. Eating out for every meal is expensive. Love a picnic. A spork is a worthy investment. (Combination spoon,knife,fork in one handy gadget).
Money - use credit cards but remember to set up direct debits to pay the minimum amount so you will never forget a payment and incurr extra charges. Then use internet banking to pay off more as and when you need to. Get currency for your next destination BEFORE you travel there. Nothing worse than looking for an ATM in a new city, after a long journey, especially if its late in the day.
Drugs - as in prescribed drugs. Get an appointment with a Travel nurse/clinic at least 3 months before you travel to find out what you need by way of vaccinations. Be warned it is expensive. Normally NHS doctors will only prescribe 3 months worth of prescription drugs. When these run out you will need to see a local doctor for a repeat, so take a note of what you need and the dosage etc. However, most typically prescribed drugs can be bought over the counter at the high street pharmacy. Be warned though, my run of the mill blood pressure tablets were not available in Montenegro, they had not been passed as `fit for purpose` there. Also worth looking on the internet as some drugs can be bought cheaply there.
Valuables - dont take any! If it would break your heart to lose it, leave it at home. Don`t advertise that you are worth mugging.
Travel kettle - if you value your cup of tea/coffee in bed in the morning pack a travel kettle. It seems drink facilities in hotel rooms are not standard in Europe. We bought a kettle in Koblenz for 15 euros complete with mugs and spoon that pack inside it when not in use.
Reservations - book seats early if you are travelling as a couple or in a group. Especially long haul journeys. It costs about 4.50 euros extra but its worth it. Also, if you can`t get a seat there is no standing allowed, so you could find yourself stranded if a bus is fully booked.
Communication - good idea to have ONE person who knows where you are. Text or email them on travel days saying where you are travelling from and to. Don't confuse things by having `Chinese whispers`.