I really can't stand laying track. Well maybe that is harsh, I really can't stand ballast. It just seems to be there to muck everything up.
Here is what I have found after laying a lot of track.
1. Use track nails to hold things in place. I've had so many problems trying to get flex track to line up and stay lined up on tight curves. The only way that seem to work is to drill a small hole in the ties and put down some tiny nails at crucial points.
2. Use a Dremel tool and cut off discs to cut track. Using rail nippers is for the birds. Rail nippers never give a nice cut. The Dremel can cut nice straight cuts and you can even use it to sand off any nasty bits.
3. Solder on the outside of the rails. If you use too much solder on the inside rails then you might be creating a derailment point.