Alan it is a bit of a minefield however the manufactures all offer dedicated mixes now and I'm happy using any of the main brand dedicated Roach, Bream, Method or Silvers mixes, however the key is understanding how to mix them, how to feed and what to put in them.
Providing you have mastered the basics of loose feeding, knowing how to feed little and often, when to feed more and when to cut back, (more anglers than you realise struggle with the basics), groundbait isn't a great deal different. What you have to understand is that groundbait is an attractor, holding agent and most importantly a carrier for feed.
The amount you put in and when you top it up is critical not to mention the quantity of particles you introduce with it. There are loads of video's on Youtube with winter silvers fishing on commercials. Spend a few hours watching these and take in what the anglers say and then try it on a commercial near where you live.
With groundbait it's always best to adopt a cautious approach because once you've put it in you can't take it out. If in doubt two or three tangerine sized balls with minimum feed isn't a bad way to start. It often takes fish 1/2 hour or so to settle on groundbait so once you've fed top up with loose feed over the top on a little and often basis, noting many people fish a feeder or waggler to allow the groundbait line to settle and this can tell you a lot as to how the fish are reacting.
Sometimes they simply don't want groundbait and you'll often see anglers putting another section on and start loose feeding a section past where they introduced their groundbait. You have to play it by ear and feel your way into the session, more so in winter when bites are at a premium.
Also don't fall into the trap in winter thinking groundbait is the answer, quite often loose feeding alone can be the way to go.