You'll find out after biking around for a week or two where the main corridors with minimal elevation are, especially along the main route you take. At this poi

You'll find out after biking around for a week or two where the main corridors with minimal elevation are, especially along the main route you take. At this point after ~3 years I know 95% of the best routes to get to/from any within the city proper, and I check directions just for the ending last few blocks since that can make the difference between a steeeeeeep climb or a simple circle around 2 more blocks that's flat. I also don't have any problem with respect to no bike lanes and crowded streets though, so that might be a bit more difficult to discover. I use Google Maps and it's pretty solid at taking you an extra .25 miles or so just to get you on a dedicated bike lane within the city, and you can always streetview points on your route if you want to double check what it looks like.