I don't spray base. I have so many allergies that I don't even want to go there. I do pin, a LOT. I bought all the pins in Walmart... twice. Although my "Complete Idiots Guide" book said to pin every 6", I did more like 3".
When making the sandwich, I taped backing down tightly (but not stretched). Then added the batting and top. Taped that a bit too.
I'm not great, but never get tucks in the back. I started with SID. (Okay, I must admit, it sometimes became stitch NEAR the ditch.) But eventually did free motion on a baby's quilt. (Echoing the dinosaurs.) I must admit, I bought 3 yards of the cheapest cotton fabric in Walmart and the cheapest batting and three yards of muslin for the backing. Then I practiced. I never did well with formal pattern like feathers, but then I can't draw with a pin and paper. I do a pretty nice meander now after all that practicing.
Don't give up and good luck.