Got a job last spring where the homeowner basially said do whatever you think looks right, pick the profiles, work the schedule how you want. First time I've had that much say on a full house, and being the only trim guy on the crew meant I had to get organized fast or lose days to dumb mistakes.
Biggest thing: cut everythign you can before you install anything. I spent two mornings just running base, casing and window returns, labeling each piece with a pencil on the back, stacking them by room. When I started nailing stuff up I never had to stop and set up cuts mid-flow. Also buy ten percent extra stock minimum, more if the house has weird angles. Nothing kills momentum like a fifteen minute drive for one stick of casing. Cope every inside corner, even if you're tempted to miter. On a job where the client cares about the details, miters that open up in winter will come back to bite you. Take the extra time on the first door casing and set the reveal, then repeat that exact setup for every other opening in the house. Consistency reads as quality way more than speed does. Last thing, walk the client through once mid-job. Show them the first finished room, ask if the reveal and the profile sit right with them. Mine loved it and stopped asking questions after that, which let me just work.