Donna pretty much said it all. I used a long-tail cast on a lot, too, mainly because it's easy for me and fast :) I ran into problems because I was going too fast, however -- when I slowed down and paid more attention, my casting on got more uniform and less tight. I try to place them the same distance apart as I add each one (push them together once they're on a few stitches) and just gently tighten the yarn for each stitch. Also, as mentioned, experience is going to make a difference. I wouldn't worry too much about it unless your cast-on stitches are so tight that they pull in the knitting at the bottom.

As I mention in another thread, there are several good articles about casting on at knitty.com -- you can search their site for lots of good information.

It is a good idea to cast on over a larger needle to give a more elastic edge that won't pull in. Using a larger needle means you can snug it up for evenness and not worry it's too tight. If you want an even edge, the cable caston is slower but you may be able to get uniformity with less attention.

Try using the larger needle for now. I advise that when you cast on, you think of snuggling the new stitch barely enough to lightly hug the needle and cozy it up to the previous cast on. No tugging. You need room in that stitch to slip the other needle into it as you knit.

Thanks everyone. I'm going a bit slower which helps a lot.
Jen

As with all knitting, the more you do it, the more uniform you will become. I would just practice casting on, all by itself! Just do it when you're watching TV, endlessly, and you'll probably get to where you want to be, in terms of even stitches. The larger needle for casting on is a great idea-- you can cast on tighter that way, which will be more uniform, and then when you go to the smaller ones for the actual knitting, you'll be fine. The other technique I was taught umpteen years ago, is to cast onto 2 needles-- meaning, hold the 2 together, as if they were one, and then after casting on, slide one out. But I think using a much larger needle may be easier and do the same trick.