Using both EAGLE v4.16r2 and v5.2, I have routed relatively simple 2 and
4 layer boards, using mostly digital logic chips and CPLDs. I used both
through-hole and SMD parts. And except for bypass caps, all parts are
mounted on the top (layer 1). I've gotten pretty good at doing these
low density digital boards.
However, I recently routed a small 4 layer analog/digital board (EAGLE
v5.2) that has dozens of components on each side. This board was far
more dense than any boards that I had done before. With both the top
and bottom layers active (1 & 16), plus a spaghetti bowel of airwires, I
had some problems positioning the parts and routing the board, and I
became quite frustrated with myself and sometimes with EAGLE. Sometimes
it hard to know if an airwire is connected to a pad, or if it's merely
passing over a pad. I'm hoping that someone has a better, less
frustrating approach or strategy to dense board design, and who would
willing to share some tricks of the trade.