There is no limit to ways there are of thinking creatively. Some techniques you can begin with are:
Brainstorm ideas on one topic onto a large piece of paper: don't edit these. Just write them down.
Allowing yourself to play with an idea whilst you go for a walk.
Draw or paint a theory on paper.
Ask the same question at least twenty times and give a different answer each time.
Combine some of the features of two different objects or ideas to see if you can create several more.
Change your routine. Do things a different way. Walk a different route to college.
Let your mind be influenced by new stimuli such as music you do not usually listen to.
Be open to ideas when they are still new: look for ways of making things work and pushing the idea to its limits.
Ask questions such as 'what if….?' Or 'supposing….?'.