Well from my experience, I just gather what track I already have and throw it all on the table to make a crude design in my mind. I stay away from SCARM and other track programs simply because it takes to much time for me. Also when building layouts I try to be as cheap as possible which works most of the time. This helps as I have a lionel postwar layout and I'm able to slap a green carpet down and call that scenery. I also buy cheap but great looking plasticville buildings which fit in greatly with the theme. Wiring the layout is simple as I can't solder and wouldn't waste the money and time to buy a soldering gun. Thus I just wrap bare wire around more bare wire and wrap that with electrical tape which I extend to other areas of the layout that require more power.
Now aside from that mess, I also have an HO layout. I don't have a buss wire system for that but I would say when ballasting you have to make a certain mixture of glue and water.. It's like 40% water and 60% glue... I'm probably wrong on that but oh well.
