ok, heres how i do it, other ppl may have different methods:
1. Make sure the car is well cleaned with a decent shampoo, dry, and in the shade/garage etc..
2. Apply polish to a foam applicator pad (meguires do good ones, available from halfrauds). Autoglym Super Resin Polish is a good one, or Autoglym Ultra Deep Shine (a stronger polish).
3. Apply the polish in a back forth motion (NEVER CIRCULAR MOTION), in the drirection of airflow, as in vertically up and down the bonnet etc. This will minimise visible scratching. Work round the car, starting with the bonnet, then to wing, down the doors, round the back, and up the other side of the car finishing where u started. Finally do the roof.
4. Go and get a beverage, and drink that for 10 mins
5. The polish will have dried to a powdery state.
6. Buff off with a microfibre cloth (99p, tescos), starting with the bonnet, going round the same way u did before.
7. Either seal of wax now, will look amazing.