Keep in mind that scissoring isn't something that you can just do - it takes lots of practice, and the dogs will look choppy when you first start. There's really no way around that. I ALWAYS bath and blow dry before scissoring - if you don't use the dryer to dry the dog, then the hair doesn't stand out from the body properly, and you'll never get the right trim.
I copied and pasted the information below from the thread titled "Trimming Cocker Legs And Paws." I'm sure that Gina can add more information too.
I usually start with the back feet, but it really doesn't matter. With the dog standing on the table (use two nooses if your dog likes to sit a lot while you're grooming - just get a second grooming arm and put the second noose around the dog's abdomen), trim a box around the dog's foot. Make 4 cuts - front, back and both sides of the foot. Don't trim too close to the toe nails, otherwise they will end up showing, and you don't want that. Once you have "boxed" the foot, trim the corners of the box until you have a rounded foot. Usually the "circle" should be about 1/2" or so away from the ACTUAL foot itself, if you know what I mean. If you were to draw a circle of the dog's foot on white paper, and then a circle of what you have trimmed, there should be about 1/2" difference between the two. Then, using the comb, fluff up the leg coat until it's sticking out as much as possible. Holding the shears parallel with the leg (up and down), make a straight cut "along" the foot. This is the scary part, so you make not want to take a lot off to begin with, just do it in stages.
Gradually, you will trim a column around the dog's leg. In order to trim the hair behind the leg, I bring the leg straight forward (hold it straight towards yourself) and trim a straight line "under" the leg as the hair hangs. Trim up nice and close in the armpits, because nobody is going to see it (I usually use the clippers there).
Keep coming the hair up to fluff it and make it stand out, and then trim. Always hold the shears parallel with the leg, up and down. Holding the shears that way, you get the least amount of scissor marks on the hair. As you get better, you will spend more time fluffing and trimming tiny hairs away, until your column looks nice and even. Keep in mind that this works best on Cockers with fluffy coat. Cockers with nice, correct coat are a bit harder to trim this way, because you can see each scissor mark more clearly. This is just a fact of life, and as you get better at this technique, you will notice the lines less and less.
I tried using clippers with a comb over the blade, but I could never make it look nice. So I always use scissors on the legs. For trimming the legs I use 7" straight shank shears - you can get Dubl Duck scissors for a good price. You don't need to spend a fortune, but do spend around $40 to get a decent pair. I always trim from above - so I stand over the side of the dog and cut with the scissors pointing towards the ground.
If you are getting choppy scissor marks, you are probably taking too much hair at once. I can take quite a bit of hair now, but when I was first starting I made small cuts. It's a lot harder to completely screw up a trim when you're using small cuts. And when you've done the bulk of the work and are just tidying up the cut, use extra small snips, and just take your time. I do LOTS of fluffing of the coat before cutting. Trying to cut hair that's hanging down is next to impossible. That's why if you can teach the dog to lay down for blowdrying, it really helps. That adds volume to the coat (drying it from underneath, essentially), and makes it a bit easier to trim.