I just re-read your original post and realized my three ring advice might not make too much sense for your two ring bike. The general principle still applies, so you would want:

• Small ring -- gears 1, 2, 3
• Big ring -- gears 3, 4, 5

So, find the gear you're comfy in, maybe it's small ring/2nd gear. When you want to shift to higher gears, go up to 3, but for your next shift, go up to the big chainring. Likewise, when downshifting, When you get back down to 3, go to the lower chainring on your next downshift.

Basically, if you're on the low ring, you want to be in a low gear, and a high gear on the high ring. That avoids overstretching the chain. Like I said, it becomes automatic with practice.

And I realized today as I rode up a long hill, sometimes I do "cross shift" or whatever it's really called when you shift down a ring and up a gear simultaneously to be in just the right gear for a long, steady climb.