What kind of hibiscus is it?
Since you say "tall and lanky" I'm initially thinking it's a texas star (Hibiscus coccineus). Mine does that and yes, you can trim it to make it bushier.
Actually, as far as I know, you can trim about any hibiscus to make it more bushy.
The thing is, if it's a tropical (H. rosa-sinensis), then it'll be 3 months before those branches recover enough to bloom.
You don't "have" to trim or pinch any hibiscus, but most types bloom on new growth, so doing that will give you more blooms. Just depends on the look you're going for.
Barb

What type of hibiscus is it? Is it a Rose of Sharon? I cut back my hibiscus just prior to winter. They bloom on new growth. My ROS are pruned in the Spring to maintain a dwarf tree shape -- each one is unique. Good luck!

Sorry I haven't got back to this forum.... My hibiscus is a huge dark red bloom, not a rose of sharon. This year the Jap. beetles have taken over and are ruining it, but next year maybe I should cut it back a couple of times?... I've seen some nice busy ones about 2 ft. tall - maybe that's a different variety. Thanks.

I believe I have the same hibiscus. The blooms are huge and beautiful shade of red. Those darn beetles just about chewed all the leaves (they look like swiss cheese, don't they?). But I have seen 3 flowers now so I think the bush/plant will be alright. I did cut mine back last year after it flowered the last time (late fall, early winter-after the first frost) and it came up nicely this spring, looked great until the beetles started coming around.