Just went through this. Here is my top 5 suggestions:
1- Use the "template method".
2- Remove the toilet, and as much other stuff you can (pedestal sink,
small vanities, removable cabinets, etc.) Ideally you have a perfectly
empty room, with nothing in your way, no extra cuts to deal with, etc.
Removing a vanity is not always hard -- mine was held in with just 2
screws, basically, and some easily unscrewed plumming.
3- Remove the toilet.
4- Don't try to work around the toilet.
5- Use one of those fancy rubber wax rings. Yes, plain old wax rings
have been around for a few millenia I am sure, along with the
doubling-up trick when needed, but they are are easy to screw up, and a
leak is a bad thing. The extra $1 or whatever for the fancy modern kind
seems a tad more idiot-proof.