this week i took my machine, a pile of fabric from a frustrated project and paid for an hour long lesson at my lqs. it was worth every single penny of the whole $10 she charged me.
maybe taking something very specific project like you are working on and going through the steps would help you too. i asked her to sit with me for every step; the seam, the cutting, the piecing, the pressing. i got some great little insight into the things that are cumulatively to blame for my less than accurate piecing.
might be worth it
aileen