I've been doing this with some of my manual cameras. Meter something appropriate, enter settings, and go. The problem is when I enter deep shadows, nothing has significant light on it, photos come out too dark. That's when you learn to open up a couple of stops. Metering every frame is just silly, frankly, unless you're shooting chromes.

The Contax 35mm SLRs (RTS III and later) have an interesting AE Lock function. The usual method is to meter, press the AE lock button, recompose, shoot. The Contax AE Lock switch gives the camera an Exposure Index priority setting, allowing you to lock in your exposure values for as long as the camera remains on, all the while allowing you to change aperture settings, or switch to Shutter priority... It's a great feature that I never see discussed. It's a manual exposure mode that is fully automatic!