I find that a lot of the work is in prepping the lips.
So a good lip scrub with a soft toothbrush, wipe off the excess with a soft, damp cloth and then apply lip balm/oil.
Do that first before you do the rest of your makeup.
Lip liner is essential when wearing lipstick (for me anyway) as I find it stops the lipstick from bleeding away from the lips.
Make sure it's sharp, pop it in the freezer for 5 minutes to ensure that it's firm enough to apply a precise line, instead of a thick one.
When apply liner to the Cupid's bow, bring it down on to your lip slightly (from both sides, in an X formation) to add more definition.
Then, as others have said, powder your lips lightly, add lipstick, blot and repeat again.
Add a small dab of clear gloss to the middle of your lip to make them look fuller.
I find that smacking your lips together can smudge lipstick and make it look messy.
Lipcote as a top coat stops it from going anywhere but if I use it I have to also use gloss as I find it quite drying.
As for colours, have a google and look at complementary shades for your skin undertone. I have a warm tone so find coral, peachy and brown nudes suit me best.
There's loads of charts and swatches on google to guide you.
It's so important to find the right tone if you want to wear red lipstick; I found that I always looked like Coco the bloody clown until I found the right shade for me.