Well I normally practice different techniques. You can do the same riffs but with a different technique it sounds totally different. I play a 5 sting. I may go to a 6 later and I need a 4. But let's stick w/ the 5. You can practice the open-hammer-pluck technique. and I'll abbreviate the rest. OHHP, OHPP, OHOP etc.
I also practice drum rudiments on my bass w/ the notes.
Ex. paradiddles, double paradiddles, triplets, ratamaques, flams
You can also try a trick I learnd as a drummer and play in a different time signature. But don't do it for too long lol. For instance, if the song is in 4/4, play in 5/4 or 7/4 just to try something crazy. 6/8, 6/4 use your imagination.
The double thumb technique (Vic Wooten) is always fun to practice as well as double and triple plucking. It takes a while to develop.
2 handed tapping is really fun to practice although it is rarely used in Gospel but it's all just practice. And practice everything slow and musically. It does no good to know a technique but not use it musically. Just use your imagination.
Oh I almost forgot. When you practice these techniques, ex. paradiddles, each time you hit or pluck a string change notes. Thumb, pop, thumb(2x), pop, thumb, pop (2x).
I hope I was able to help. When I get a decent web cam I'll post some stuff on youtube.
