You might try using one size larger needle if you knit tightly. However, experimenting with holding the yarn different ways for tension is good too. You have to find what is the most comfortable for your style of knitting.
I knit a little looser with Continental knitting. I am comfortable with the way I hold my yarn, so I sometimes just go down one size of needle and it works out fine.
~Knit for Charity~
"that their hearts may be encouraged, being knit together in love" - Col. 2:2
TXMcKnitty on Ravelry