Book hotels with many suites, you aren't going to get an upgrade at a courtyard if it only has two suites.

Shorter stays. Hotels are more likely to give you upgrade for 1 or 2 night stays vs 7 night stays.

Have no expectation of upgrades beyond higher floor rooms and you'll be pleasantly surprised when you do get the suite upgrades. There is a gluttony of platinum members, so being Titanium helps.