I'm not a fan of pins or basting tacks, because when I'm quilting I get on a roll and don't want to stop and remove basting aids.

Sharon Schamber has more than one YouTube video demonstrating thread basting; I've heard nothing but good stuff from quilters who try this.
I use O'Sullivan's Quilt Basting Spray (it comes in a pink can). It does have a smell, and no matter how careful I am, it does go places other than the quilt when I spray it. I always spray baste outside (I put an old vinyl tablecloth over my outside table). Since I'm in an area where it's not sunshiney all the time (as most of us do!), I tend to baste a number of quilts at once when I have a decent weather window.

I've basted quilts this way and folded them up and left them in the UFO pile for months before actually getting to the quilting part. Just a quick go-over with a steam iron will remove the fold creases and get the basted quilt ready for quilting!
It truly is easier to machine quilt (straight or free-motion) on thinner battings, and I think (JMO) that non-poly battings are easier to quilt through, also.
You can use your new walking foot for very gentle curves, so don't think that you're limited to just straight lines and cross-hatches. Just remember to go fairly slowly. It's a
walking foot, not a running foot!