I haven't been ebiking for long but I find that, though it sounds obvious, just be happy to bumble along rather than feeling like you have to be a racer all the time. It's great to go as fast as you can sometime (I managed 23mph on a downhill bit, pedalling like fury the other day)
. But it's nice to just take it slowly and admire the scenery when the mood takes you.
I usually aim to stick in as low assist as is comfortable and just play with the gears until it feels right. I live in a hilly area, but that way I am rarely using more than 3 out of 5 assist and I never use less than gear 1/6, more often 3/6, except on really steep hills. That keeps the battery sweet!