Transportation within a town:
Walk or borrow a bike. This will take more time, but again, it either time or money. It wil ltake time to walk and it tiwll take tie to find somebody who is lending you his bike. But the amount of money saved is huge.
Cook food yourself
This is a great way of learning new recipes and sharing.
Stop buying convenience food
I have never been a fan of it anyway.. but you might be. Always carry a snack around so you won`t stare in case you have to wait for a long time until you ge the opportunity to cook food. That way you are not dependent on food or other people.
Long distance Transportation: Hitchhike
Learn the local habits:
Find out from locals how to travel. For example. If you ride trains in Germany on the weekends, you could do that for free. Week-end and group tickets make it happen. I usually just get on the train and ask people. Make sure you are there about 10mins before the train leaves. Not possible in intercity trains. I learned this from my couchsurfing hosts!
Avoid going out:
To bars/restaurants, alcohol or even better organise a park-gathering or attend home-parties. They are more comfy anyway and more relaxed.
Avoid going to large cities at all!
Big city = big money..
Join free events
Museums have free days. Walking through town and taking pics doesent cost anything. Organising a pick-nick/jam-session/games afternoon in the park doesent cost anything and you will meet so many nice people. Some of these friendships will come in handy at a later stage. Don`t just stubbornly focus on yourself and what you neeed, you would be foolish. Spending time with other people will give you so much more.
Learn soemthing new from other people
Thas is free and lots of fun!
Stay over at locals
There are several different ways:
Servas (you pay a small fee as far as I know)
..... or just do it the old fashioned way and talk to people on the street and ask them if they could let you stay for the night. In rural areas and poor countries more likely.
Alternatively: carry a tent and just camp out :) yeahhhhy
If you follow all these tips, you won´t use that much money anymore. Also, when you travel, you do have more time (usually) and then you can invest some time in finding other ways of "getting/acheiving" things. Like biking around town might take much longer, but it is healthier and more fun!
This list is endless if you are just creative!