Not really. You just have to avoid apps with large memory footprints and use those that can go into the SD.
Apps2SD is an app you should have and it lets you flush app caches once in a while.
There are some ways though to cut down on internal phone memory use. Are you using HTC Friendstream? That tends to create really large contacts files due to higher resolution portrait images it would sync from Facebook. It also creates large caches for Twitter and Facebook streams.