Sketch Book
One thing that you should have if you have a deep passion in designing is a sketch book or a file. The sketch book or file will be used to store all your sketches and ideas. Besides it acts as a proof of your work, you might also want to refer to it at the designing (using software) process. You will also have a clear idea on what you are doing rather than moving your cursor around your computer screen lacking of idea or do not know what else to do.
Q: What you should put in your sketch book? Just sketches and design?
A: You can write down anything you like.
- Tag line which intrigue you.
- Future planning.
- Potential clients.
- To-do list.
- etc.
It’s not limited really. But I suggest that you should have one which is handy so that you can bring it along where ever you go. And don’t forget a pen or pencil. 
Q: How having these things could help you?
A: Personally, I have a file and a sketch book. Since then, I am more organize than before. It’s easy for me to search for previous sketches or design. I’m also clear about what I should do first and next. There is no doubt that you can sketch on a paper, but keep it organize (in file - I did). Try it! I’m sure you will love your sketch book. 