If you've done a bit of painting (Spray) in the past, you can get a good finish with a decent aerosol, but the quality of the finish is very much down to preparation prior to putting on any paint.

Once sprayed, don't be tempted to start rushing the finishing process, have the patience to leave it until it's fully cured and you can go over it with an ultra fine wet and dry (1600) prior to polishing it with something slightly abrasive such as Autoglym Polish.

There is a knack to it, and some practice is needed, plenty of YouTube videos about getting a good finish with an Aerosol.