trail and error not so much. Afterall, if not just following the pictures or instructions from some online sites, the idea behind modding or doing an effect from scratch is actually part of electrical/electronic engineering
if iam in your shoe, i will
1) Read thru over and over again, having some basic ideas of effect, switches, pots, power supply, bias voltage and buffer etc, from jack orman's site, geofex, beavis audio sites, diystompboxes.org etc
2) Learn to read schematic.
3) Sleep less, and read more
4) buy a breadboard, multimeter, soldering iron, table lamp with white light
5) Find some mods thats available online on certain pedals and try it out for fun
6) Other than reading, equal amount of time over thinking bout circuit and actualy tinkering of circuit will yield better result
7) Planning more visit to simlim tower or buying components online
8 ) be prepared that nothing will work for the first few times
9) destroying things will help creation. So so be scare to destroy ic chips, burnt it or so as long as knowing what to do and what not to do. As long as no major accident
10) Trail and error, after knowing bout whats going on.