I have been working on a scarf for my wife using Red Heart worsted weight yarn. I've put many hours into it and have produced about 27" worth of scarf that looks, to be honest, pretty darned good. It has been tedious because my knitting is tight (probably beginner death grip) and the yarn is light. It's 30 stitches wide (7") of garter stitch.
So, feeling a bit cocky about my growing skill, I picked up some Lion Brand Thick&Quick Chenille to knit a scarf for my MIL's birthday. I figured that it would be a no-brainer - 14 stitches across of stockinette. WRONG!!! I've had more problems with this yarn than I'd imagined. My knitting is ending up super-tight and incredibly uneven. I actually only got about 3" done before I ripped it all out and started again. This time, things went better (although I resorted to garter stitch) although it was still uneven and difficult to deal with. When I counted up stitches on my last row, I realized that I'd picked up a stitch somewhere. I tried to un-knit it a bit, but ended up just unraveling it all.
So, I am going to take a break from it today and may start again tomorrow with stockinette again (which the pattern calls for).