I gave you a little
sneak peak of my master bathroom makeover the other day, and I thought I'd go ahead and share with you the process I used to paint my ugly burgundy laminate countertop.
STEP ONE:
Before you touch your countertops get a really clear idea of what you want the end product to look like. I wanted a subtle travertine or tumbled marble look, so I bought a few samples at the store (and kept the receipts so I could return them when I was finished...oh, don't look at me like that) and then I held paint samples up to them setting aside any colors that I found in the stone. If you look closely you should see several colors in there.

I eventually narrowed my colors down to 3 and then bought a quart of each in latex. You could also use craft paint, but I was afraid it wouldn't hold up as well and I'm really picky about what colors I like so I went a different direction. Also, I would HIGHLY recommend that choose colors that have similar values (or lightness and darkness). I personally think if there's too much difference between the values it doesn't look real...but that's just me.

STEP TWO:
Do a couple test boards using the techniques below. Create as many as you feel you need to do until you like the outcome. This was the final test board I did...and actually I may like it a little better than my actual counter...but oh well.... :).

STEP THREE:
Clean your counters REALLY well. Make sure there's not dust, gunk, residue...or what have you...left behind.
STEP FOUR:
Lightly sand the counters. And then wipe them again so no dust is left behind.
STEP FIVE:
Use a really good oil based primer like BIN, and paint a coat of primer. Let it dry at least 4 hours, longer if you can.

STEP SIX:
Paint a base coat over the entire counter. I used the lightest color first, then applied the medium color, and then the darkest...but I'll get to that part. Let the base coat dry at least 24 hours. I let mine dry longer than that and I think it helped it set up a bit before I applied the next color.

STEP SEVEN:
This is the part I was terrified of because I'd never faux painted before...it really wasn't as hard as I thought it would be, though. And really, if you mess up you can always add more paint, or even repaint the base coat if you need to. Repeat to yourself "no stress....no stress..."
Lightly dip a slightly damp (but not wet) paper towel in your 2nd paint color.

Lightly dab it onto the counter, being sure that you're putting it on lightly enough to let the base coat still show. I think it's better to start applying the paint kind of sparingly and then add more later if you feel you need to.

Let it dry at least 24 hours. Oh, and if you're anything like me your hands will look like this after this step.

STEP EIGHT:
If I thought I was scared of the second color, I was shaking in my boots by the time I needed to apply the third color. After all that work I definitely didn't want to mess it up at this point. But again, you can always fix it....no stress.
Since I wanted the color of the counters to be really subtle I mixed some of the darker wall color with some clear glaze. I then used a damp paper towel to randomly apply darker sections to the counter. This is where I REALLY studied the patterns in my sample tiles.
I was worried it was still going to be too dark, so I went back over each section (immediately after I applied the paint) and misted it with water and then blotted and sometimes buffed with a damp paper towel.

STEP NINE:
Apply at least 2-3 coats of a non-yellowing polyacrylic topcoat, letting it dry a day between each coat. I used polyacrylic rather than polyurethane because A) I've heard polyurethane can yellow, and since I was using such light colors I didn't want that to happen, and B) I had several different paint stores tell me that since polyurethane is oil based you can't use it over latex paint. I don't know if that's true or not, but I didn't want to take a chance. I think if you use oil paint rather than latex you can use polyurethane just fine.
FOR THOSE OF YOU WHO WANT A GRANITE LOOK:
I've heard with granite you want to use more of a
splatter or
sponge method than a
dabbing method, so it's more speckled and less blended.
Also, a while I saw
this post where a woman had used that speckled stone-look spray paint to just spray her counter and then applied a top coat. She used a charcoal grey version of the paint, and it really does look pretty amazing.
HOW DOES IT HOLD UP?:
Since I painted the countertop fairly recently I can't give you a definitive answer on this, except to say that mine has held up great so far and everything I've read says they hold up reasonably well (as long as you don't poke at it with a knife or anything like that). Also, I'd be careful about having anything like hot pans or curling irons on the counter. But really, for maybe $30-$50 and a whole lot of satisfaction for not having to look at an ugly counter anymore, I think it's worth it.
AND SINCE EVERYONE LOVES A GOOD BEFORE AND AFTER PICTURE:

I hope this is helpful. Feel free to let me know if you have any additional questions.