I can help a lil thats on a invisable plant
anything dead,diseased& unproductive.
anything overly tangled/crossing
cut to direct growth or to reduce some growth.
when you trim the tips on your round shape it will help keep it full.watch for the thorns,they really do hurt& hurt worse than rose
Fence one.I guess you'd locate your longer branches and drape to cover the fence and the side stems that come off them you'd trim the tip so would flourish out.They like acidic soil.maybe try to mix some azealia potting mix in the existing pots.I don't grow mine in full sun,but they do get quiet a bit of sun in morning& evening.I cold GH mine,but they'll useually bloom all winter for me,but I trimmed them so no blooms this year,but mine will start up in May.I grow mine in hanging baskets.I'm a zone
8b and they are hardy to zone
9.I have wet winters....or I'd try growing
them in ground.I keep mine on the dry side durring winter from Dec- Feb.
Sorry not much help.I had a good site bookmarked,but when got computer worked on I lost those good bookmarks.I will look for it a bit more.it had lots of good info included.