Are you using the LUS charts or the new ones? I haven't looked at the new ones much since I got off the bus last year but if your route is 10000 feet or below you would be fine not doing the depress routes. We used them a lot out of PHX since almost all our routes in Mexico went down the Sierra Madres. I liked the new charts when I saw them.

If you are off airway just use the 80 mile circle to figure out where your nearest entry point should be.