My strategy has been 1) Ride affordable bikes 2) Use at least 1 quality lock and 3) be strategic about how/where you park or store your bike. Be sure to lock up in highly visible areas covered by cameras if you can and lock to objects that would be difficult to cut through. Most thieves use a battery powered cutting wheel these days.

The locks I use vary depending on the bike/situation but typically, I am using a Skunklock Chemical, Foldylock Forever, or Hiplok Gold (or some combination thereof) and also sometimes a cable and cheaper Kryptonite U-lock for added security. Most of my bikes also fold, so I typically bring them in with me both at home and work (sometimes even into stores - my Portola ebike and Priority Folder bicycle both fit under a shopping cart).

If you have a nice e-bike, you should also get insurance, add trackers, a motion alarm, and brake locks. A good cut resistant u-lock like the Litelock X3 would be a good choice for a primary lock.