It depends on what I’m targeting/venue etc.Are you mixing it with any other bait or just using it as it is and fishing over the top?
For barbel specifically I tend to add it to a method mix and wrap it around the lead or ball it in if the situation permits. I’ll also add a light scattering of my hookbait choice in the wider area. Alternatively if I’m in a tight swim and want a bed of bait down then I’ll use a bait dropper, omit the groundbait and add hookbaits to the mix.
With regards to carp fishing I’ll spod/spomb/spoon it out depending on swim choice and venue. I don’t subscribe to the notion that bait has to be overly flavoured for it to be effective so less is more in my very humble opinion.
I should add that for the most part I’m fishing canals, small rivers or the upper Trent. So my approach may be limited on your choice of venue.