General

Like what @wall said, using a mouse to draw digitally is an art itself (All the respect to people who can draw incredibly well with a mouse)

I use a Wacom Cintiq (if you dont know what that is just copy and paste the words to google) as its easier to use and a samsung tablet or the good old notepad for on the go purposes

I tend to do what @Lemonfizzeh said. I do some doodles freestyle with my mouse sometimes but its more for fun than actually doing something good

I always draw by pencil on paper, and later scan it to my computer. I then use some photo-editing software and trace everything with those lines that you create by dragging the cursor, and afterwards I just add colors and smudge them or whatever

I use two small Wacom tablets (a 2010 Bamboo Pen & Touch Small and a more recent Intuos Pen S), but there are cheaper alternatives available. Monoprice has tablets that are good value for money as long as you live in the US (their shipping costs are [i]absurd[/i]), if you live outside the US you could try a Huion instead.

Wacom is arguably the least finicky out of the three (both Monoprice and Huion have driver issues, apparently), but any tablet larger than Small is pretty darn expensive.

I use a mouse. Too cheap for a tablet.

draw A LOT. get used to the fact that you won't be able to achieve the same pressure effect that tablet users can do

what the guy above said^ but i dont think wacom tablets come that cheap? unless he meant a preowned one