Re: Key to a good finish
As far as the basic process you've done I see no flaws; wet sand then polish. One suggestion I'd give for you to consider is to wet sand up to 3000 - 3500 grit micro mesh before you start polishing.
I'm not familiar with the polishing compounds you have used but in general there are 2 posibalities that come to mind related to the polishing part that could leave fine scratch marks.
1. The first compound you use after wet sanding is too fine where it doesn't fully remove the scratch marks from the 2000 grit wet sanding.
2. The final polishing compound you used is not fine enough and that is leaving the micro scratches in the finish.
Another thought is that it is possible somewhere along the wetsanding process you didn't fully remove the scratch marks from the previous grit used; ie. You didn't sand enough with the 1200 grit so marks from the 800 grit still remained and never got rubbed out throught the rest of the process.
On a similar note when wetsanding the sandpaper can get clogged easily. If you don't keep it clean enough or get a new sheet the particles caught in the sandpaper can cut into the finish and not get buffed out.
The key to doing a perfect finish it to have patience and take your time. Like I said I don't see anything wrong with your basic process for finishing. Tips, Take your time, keep the sand paper clean & switch it out often. As far as when to swap from one grit to another, for me it's hard to explain, you just have to have done it enough and go by feel. Maybe wet sand to a higher grit before polishing and/or try a different polishing compound (I've used the colortone ones from stewmac with wonderful results).
I hope this helps some and good luck!