Blocking always makes a big difference to the finished look of anyhting knit with a fibre containing enough natural content. You can find lots of good instructions on the Net - try Knitty for an introduction.
Um... for cables... well they're not as hard as you'd think so don't be discouraged. Be careful not to split your yarn when you're transferring the stitches. Once you have a good understanding of what you're doing and how, you may find it worth learning to cable without a cable needle. That extra needle can be fiddly.
If you knit tightly and find the stitches too stiff to rearrange, try knitting the cable stitches a bit more loosely on the row before you cable.