There are many times when it gets to us all. Pressure. Whether it be from peers and comrades pressuring us to get-r-done, from ourselves just wanting to finish something or maybe in some cases pressure from a customer. What we must all take to heart is, haste really does make waste. The projects I have had the greatest success with are those in which I ignored all outside influence. In this way I found that not only was I able to work at my own speed, but was able to focus well enough that I could work steadily, and cleaner than normal.
Take an extra moment to measure something a third time. Make an index card template so both sides match and by all means spend time sanding and polishing until YOU are happy with it. Ask as many questions along the way as you need to, but don't let our cajoling rush you and cause you a mess. Now, with all that said JUST GO and BUILD the damn thing wontcha?