My friend taught me to knit.
She got me started on a simple KNIT scarf.
Once I was done with that, she showed me to PURL, and had me do anothe scarf in seed stitch (Knit 1, purl 1).
I then saw a pattern with cables. I fell in love with it and tried it on my own. It looked so wrong to me. I asked my friend for help. It turns out I was doing it right.
So my best advice is , PRACTICE PRACTICE and them PRACTICE some more