Currently:
1) Don't blob up through war at all.
2) Stay a naval power; only expand through colonization and only force-take the occasional province I needed for colony/ship range and/or resupplying (for example Gibraltar from Granada to ensure colonization is possible in the first place).
3) Be under the influence of the "Liberte, Egalite, Fraternite" cultural decision. +8 global revolt risk keeps a country of islands exciting, and at full innovative+freesubjects+L,E,F even techs 20-25 years ahead of time just cost ~6000 ducats for a large nation. This may not so much be a house rule as just a thing I do, though.
4) Stay under the BB limit (although with a crappy dip doge, the navigation act, privateers, very hard difficulty, etc, it's a limit of 10. Ouch.)