I wouldn't always go with that, I don't have photoshop but I have done simple stuff with Paint and if you use it carefully you can get stuff to look OK.
I turned this:
Into This:
And this:
And I made the logo and flyers for my site all on paint:
I made my dad's signature on paint. The Woody is made from a blue 4 door, I turned it into an estate, added the wood, lowered it, changed the wheels, added roof rack etc. I made the Grey MK1 from a green 2 door Cartoon that I found in someone elses sig, turned it grey, lowered it, changed the wheels, etc. OK, I may have mixed and matched from other peoples sigs a bit but I put it all together on mspaint.
Made this aswell:
I know that for more serious stuff and better quality you need photoshop but some simple things can be done on paint OK