Here's my technique. It gets me at least 5 days without chipping (more if I'm using a crème or jelly), and I'm rough on my nails.

Start with both hands:

1. File and shape your nails
2. Using cuticle oil and a cuticle pusher, gently push back your cuticles (don't trim them!)
3. Wash your hands thoroughly
4. Use 100% acetone to clean and dehydrate your nails

Take a pee break now because you don't want to mess with a fly or underwear with wet nails.

Now work on one hand at a time:

5. If you have ridged nails, use a ridge filler to achieve a smooth surface to work with; otherwise, consider a coat of strengthener
6. Apply a layer of base coat (not too thick or thin)
7. Using a good quality self-leveling polish, apply one thin coat to each nail. Go slowly and be sure not to flood your cuticle (there should be about a 1mm gap of empty nail between your cuticle and the start of your polish). It's OK if this coat is a little patchy because most polishes don't give single-coat coverage, and self-leveling polish will automatically smooth out some unevenness, but do your best to get it even without making it too thick. Use an angled brush with 100% acetone to gently remove any excess around the edges of your nail.
8. By the time you finish one coat on each nail on this hand, the first finger you painted should be dry. Apply a second thin coat to this hand (always starting with the same finger), being sure to also paint the free edge of the nail.
9. Depending on the finish and color of the polish, as well as your nail length, you may need a third coat. Same instructions as 8 above.
10. Apply a layer of good quality quick-dry topcoat, again painting the free edge of each nail. This layer can be generous but not tooooo thick.
11. DON'T YOU DARE TOUCH ANYTHING for at least 10 minutes. Seriously. Listen to a podcast or watch the birds through your window, but you will fuck up your polish if you don't let it set. (Do I ever follow my own advice? No I do not. If like me you end up mildly fucking up your polish, you can probably use your tongue to very gently massage it back into place. Yes it's gross but it works!)
12. Once your polish has sufficiently set, you can paint the next hand.

Some product recommendations:

• Germanikure nail file
• Germanikure cuticle pusher
• Cuccio cuticle oil
• OPI Nail Envy strengthening treatment
• Orly Bonder base coat
• Mooncat Speed Demon topcoat

High-quality brands which tend to have self-leveling polish:

• ILNP
• Cirque Colors
• Mooncat
• OPI
• Orly