1. it can get pretty boring when you're limited to those silly little lines that they give you in MS Paint-
. So with any of the drawing tools (line, spray, eraser, pencil), you hold ctrl and press the + on your numbber pad a bunch of times, your medium's(line, spray, etc) drawy part gets bigger .
(the only problem you may have is when you try to undo something when using the pencil tool it wont get rid of everything.
you can basically make your own brushes in paint. All you have to do is draw something.
Select it and make sure the transparent setting is on
and then hold shift and click, then just move the selected part out of the way and there you are!
Now if you want to make some cool looking 3d stuff, then just hold shift as you drag it and voile
3. Replace colors
Now lets say you draw this beautiful drawing of a dog-
and then you see that you colors dont look good together . So you use the color replacer!
first, select the color you want to replace, in the first color swatch thing-
then you select the color you want to replace it with in the other one
then select the eraser and drag across the picture using the right mouse button, and it will replace the two colors
4. Something i didnt know until recently is that you have 3 color swatches. you have one(left click), 2 (right click), and 3 (crtl + left/right click).
5. i saw a video thing on the forums before, but i dont know if this was it.
(i dont feel like making pics
open a video and start playing it.(make sure its in back of the paint screen
then go to Colors->Edit Colors-> and additional colors
make the color -
green = 0
blue = 16
then press ok and start dragging shapes over the screen.
it should show the video in mspaint, as if through the screen.
6. its basically the same thing as number one, but it scales a picture.
open up a pretty picture
press ctrl + a
press ctrl + plus(num-pad's +)
and if i happen accross any other cool tricks, ill post them here and if you have any, then feel free to post them
EDIT: i also have some not-so-much-tricks-as-niftyish-things-that-some-people-might-not-kinow. so if you want them then ask