What John said... For best practices, maybe consider making the label a stand-alone part with the graphics as an allied texture (decal).
For silkscreen, you can do the same thing in the fabricated part where the silkscreen is applied. You can use the Alpha channel to provide a transparent background when applying silkscreens. The built-in image editor will let you edit these image files for transparent background and a limiited number of other commands.
The third common method is to use the symbols which is similar to the geometry "sketch" method but is probably a little easier to manage. These can be turned on and off with the Display Annotation option. This has its own limitations of course, but that is one way to manage a lot of labeling in assemblies.
And last, you could add symbols in the drawings only. That way you only have an outline in the model, but you can place the symbol when drawing. This really keeps the models lightweight.
Personally, I still extrude silkscreens for simple assemblies. Labels may require minimal geometry to represent orientation.
Limitations: symbols can be turned on and off on drawings at will but textures/decals only show up in shaded view mode on drawings. Defining labels in a hybrid mode, symbol and decal is the best of both worlds. Managing symbol libraries may be a downside but once inserted, it is part of the model/drawing.
