For inspiration look at the 4 volumes of RH Clark's An Historical Survey of Selected Great Western Stations, the link goes to an advert on anazon for volume 2...
https://www.amazon.co.uk/Historical-Survey-Selected-Western-Stations-x/dp/0860930157/ref=sr_1_fkmr1_1?ie=UTF8&qid=1502562634&sr=8-1-fkmr1&keywords=gwr+stations+Clark
They are full of all types of mainline, secondary main live, branch line, double track or single track stations all with track plans.
Well worth the time and money to get your hands on them.
Duncan