Hat Pattern decreases

I found a nice rolled hat pattern that went to a child 6 and added a few stitches to make it a tad bigger… but didnt realize the decreass may have needed to be changed before the pattern called for the start. The hat turned out fine but my question is this:

Do the Darts that start for the decrease… is this the line to follow to know how many to decrease when your creating your own patterns. And should that decrease for the dart need to be the first stitch in line with the previous decrease or the next one…?

Also…on a Knit 2 Purl 2 rib stitch… when it suppose to end in a pul… is the cast on even or odd?

And last… when adding a new color…I am gettting the “V” stitch for the st st… and getting a very large stitch notice and also when I am adding the yarn and using the tails in the first 2 stittches to bind it in… its causing the previous color to show then any advice?

ANd really really last…best way to darn in those ends with multi color strips… or just in general

Thanks ahead

For a k2 p2 pattern you need an even number of sts that can be divided by 4. So 60 or 64 or 68 works, but not 66 or 70. For the decs, they usually follow up the same line, you knit 1 less st between the decs on the following dec rounds. To change colors and how to knit in the ends as you go, look at all of these suggestions for doing it. I don’t like to knit both ends together because the st is very bulky. I just knot them, and they don’t show.