Is it worth fighting the machine for appliqué, or just hand stitch everything?

Hand stitcher here, no regrets. I did a denim jacket a couple years back with felted wool shapes and tried the machine zigzag first on a scrap, and it always looked a little stiff and plastic-y to me, like the edges were laminated. The blanket stitch versions I did by hand on the couch over a few evenings still look good after prolly thirty washes, edges soft and slightly puffy, no lifting at all. So for me the durability answer is that both hold up fine if you do them well, but the hand one ages nicer because the fabric can still move.

On attaching, I do use a light fusible to hold the shape while I stitch, but I cut the web smaller than the shape so no glue ends up under my stitching line. The glue can stiffen things and gum the needle over time. Pin and go works too, but clouds have wobbly edges and mine always shifted. If it were an everyday garment I would still hand stitch, just with shorter stitches than I use on decorative pieces. Ten minutes of machine time versus three evenings is real, but honestly the couch time is half the reason I sew. Your embroidered outlines plus blanket stitched edges will look deliberate in the good way, like you meant every stitch.

I'm on the machine side of this one, and I'd say the durability question is mostly about what's underneath, not the stitch itself. I've done a bunch of kid t-shirts with machine applique, three washes a week for years, and the shapes outlast the shirt. The trick that worked for me was a fusible web on every shape plus a layer of tear-away stabilizer behind the fabric while stitching. Without the stabilizer the zigzag tunnels and puckers no matter how slow you go.

For clouds on a thrifted cotton shirt I'd fuse them down with something like Heat n Bond lite, then run a narrow satin or zigzag around each edge in white thread. Ten minutes of machine time, like you said, and it holds through constant wear. The hand blanket stitch is lovely on wool felt and jackets where you want a chunky decorative edge, but on thin cotton shirt fabric it can pucker the ground fabric if your tension is off, and fixing that by hand is miserable. Where I'd actually slow down is the embroidered outlines you mentioned. Those few details by hand give the piece personality, and that's where the couch time pays off. Let the machine do the holding-down work and spend your stitching hours on the parts people notice. One practical note: test your zigzag on a scrap of the actual shirt hem or side seam if you have one, becasue some thrifted cottons are worn thin and need a wider stitch than you'd expect.

I read what you said about hand stitching looking nice after thirty washes, but I think you might be overlooking how high-traffic items really fare. When you are constantly wearing something, the stress isn't just washing it; it's the friction and movement of the fabric itself. For my heavier work clothes, even though the machine zigzag can look a little rigid, the layered approach with a good stabilizer underneath gives the piece a kind of structural strength that the hand stitching, despite looking softer, just doesn't match in the long haul. I'd bet on the proper machine layers for an item that sees daily use, even if the look is less 'puffy.'

I totally agree with the hand stitcher about how the finished product feels. I once tried a similar appliqué on linen for a work shirt, and the machine zigzag looked really harsh against the natural weave. To make it hold up better and stop the edges from creeping, I learned to place a tiny piece of light interfacing right under the shape before pinning it down. It gives the patch body and stops it from stretching out or bubbling when the shirt moves, which was key for my project.

I keep seeing people do these felt shapes and I wonder about the actual starting piece. I’ve been thinking about trying to cut the cloud shapes out myself instead of buying felt, maybe from an old piece of scrap fabric. If I just cut them out, do I need to make them a little bigger than I think I need them to be to account for the stitching? I don't want them to look too small once everything is done.

I’m generaly on the machine appliqué side for faster jobs, especially when the final piece is going on something like a lightweight cotton tee that moves a lot. The key is ensuring the base fabric doesn’t bunch up when you sew. I found that if I placed my fusible web under the fabric and then sewed my zigzag with the tension dialed in at 3.5, the edges lay perfectly flat without creating little ripples around the shape. For a similar project on a summer dress, I used a 100 weight polyester thread, and the resulting seam held up perfectly through over 40 washes without any fraying issues whatsoever. It really comes down to how well the weight of the patch sits on the shirt material.

Quick update—I decided to use the machine zigzag but went with the fusible web suggestion. It makes a huge difference in how the shapes sit. They don't seem to be creeping into the fabric edges at all, which was my biggest worry when thinking about wearing it often.