8. Finish your cuts and position the carpet into place. It's good that it doesn't fit too snugly against the wall, as this could cause it to bind in the middle.
9. If your carpet is higher end, and thicker, you will definitely need to rent a "kicker" which helps you position the carpet as you bang out the small humps with your knees. If you're doing that, also make sure the carpet hangs correctly on the carpet tack molding on the perimeter. Again, it's important that it doesn't go exactly to the edge if you are putting 1/4 round on top of it.
10. After you have made all the cuts, smoothed out all the slight bulges, check all areas before you re-install your 1/4 round molding. This is the last part of the job, but one that if done carefully will make it so that people will not be able to tell the difference between you doing it and a professional installer doing it.