In addition to the advice on the hooks are you using a float? If so, do you have enough weight under the float to make it really sensitive? If not set sensitive many times the fish swallows the bait before you know it. I always set the hook at the slightest nibble using a float that has enough weight to make it sensitive whem I first start fishing. If I keep missing the fish I wait slightly longer until I figure out the best time to set the hook.
If you really want a sensitive float try a Quill bobber. If set correctly you could detect a fish fry size bite with that one!
Cecil - good idea on early hook setting. Last night my 7 year old daughter caught a perch but it had swallowed the hook. She was using a bobber, worms and 2 split shot above a swivel. She had numerous bites and was trying to set the hook early with no luck. This one took the bobber under so I guess she'll need to try a little sooner.
She was upset the fish died.....