Knitting with more than one color yarn

Hi,
Does anyone have any advice on knitting with more than one color? Whenever I try it, it looks awful. It is not a smooth transition from one color to another and sometimes there’s a gap, and the row looks uneven. I really want to get this technique down pat so if anyone wants to pass any hints along, I would really really appreciate it!

Happy Knitting!

Try here
http://www.knittinghelp.com/videos/advanced-techniques

There are several methods of knitting with more than one color - fair isle or stranding, intarsia, and slip stitch or mosaic knitting. What are you making and do you have a link to the pattern? That would help.

Also, there are videos here in KH of a couple of methods which are used for different purposes usually. See if they help.