I'd still recommend using float tackle whenever possible. But if you must use a feeder, I suggest an open-end or cage feeder, medium size carrying no more than 1oz of lead - 1/2 to 3/4 best. Fish the feeder on a weak link in case it get snagged, and use a running lead method. Use quivertip rather than alarms - you need to be on to the bites quickly, especially if fishing near lilies (and if you can, do) Tench love lilies but not for the reasons you might suppose. Lilies grow best in silt, and it's the silt the tench love to grub about in.
Ron's tip about needle bubbles is a good one; these are VERY small fizzy bubbles, not great gloopy bubbles. Try not to plonk a feeder right on top of a feeding tench. Fish a few feet away and wait for them to find your bait. With a float, you can overcast and draw the float back right over a tench's head.
You can make up the feed as you go along. Use a hemp-based groundbait as the binder for your hookbait samples - worms, maggots, casters and luncheon meat are all top of my bait list. When using meat, finely chop the feeder samples and use chunks or cubes between 1/2 inch and an inch, hook embedded in them but point showing.
Let us all know how you get on.