CMaras -- I have a thread called new to accuquilt which addresses the same issue -- how to deal with precut appliques that don't currently have any adhesion on them. There are several helpful suggestions in that thread that might apply to your process.

Thank you for your reply. Yes, it is backed (minke), a little quilting, and bound. I started another applique monkey (there are three) then thought I would seek this talented, experienced board's input. I
couldn't find any info online. I think I'll send it with "a feature"- love your term!

I would iron them all onto a piece of lightweight heat bond or wonder under then cut them out as you need them...

Re SBS.....I have one too and am planning to use a lite weight non woven fusible interfacing.....sewing it onto a rough cut piece of fusible right sides facing, using 3/8"seam allowance...or very scant 1/4",cut fusible same shape as fabric piece .....believe me easier to do after sewn onto it, cut slit into center of fusible,flip out and with invisible thread tiny zigzag onto background... But, with each completed work layer...hand, arm, body.....cut out excess from back.......build from top layer to bottom layer.....not hard but time consuming....just the way I do it.....

I would add a fusible web to back. I lay them out as close as possible, cover with fusible and iron. I use a brown grocery bag or a piece from a used fusible under them on my ironing board - it pulls right off if done right after ironing. You could use a special sheet, but I always have these available!

I would be careful and use some Heat n Bond light. Can be found at JAF.

I would use a small flat paintbrush and good old Elmer's. Brush toward the edge gently so you don't cause fraying. The glue can even act as a stabilizer for the zig zagging. It does wash out completely in one wash. After gluing, allow to dry, then do a straight stitch all the way around, then zig zag. Straight stitching gives a nice but slightly puffed look to the zig zag.

I detest SBS so I would use disappearing spray. LOL

What does SBS mean?

I really love Glue-BasteIt by Roxanne. I get the EZ Squeezie bottle & it makes a perfect skinny line (or tiny dots) of glue every time. I've never had issues with it showing after it dries as long as I use cotton fabric. I've also used washable glue sticks (white, not purple -- though some people swear by the purple ones).

I think the Glue BasteIt would be the quickest secure route to go for machine stitching, but you could also just do a fusible. Instead of cutting everything in advance, here's what I'd do:
1) Iron Parchment Paper to my ironing board (or pin junk fabric to your board to protect it)
2) Place WonderUnder paper side down
3) Lay pre-cuts wrong side down on top of the WonderUnder
4) Place a Pressing Sheet or some parchment paper gently on top of the pre-cuts & tack together with an iron as per manufacturer's instructions
5) Peel off the Parchment Paper & cut out the fused fabric + fusible units
6) Peel off paper backing & fuse to your background fabric

The only time I wouldn't do that shortcut method is if you are using larger pre-cuts (3"+ wide and long) that would benefit from being windowed (cut the center out of the fusible, leaving only a generous 1/4" of fusible to press to inside edge of pre-cut). Windowing makes the finished product softer & gives it a better drape, especially with larger applique pieces. Nevertheless, I've done applique without windowing -- before I knew better -- and it still was a snuggly little baby quilt. You will save quite a bit of time if you don't have to window.