Finishing and blocking

I just finished knitting a raglan sweater for myself using Subline merino DK. Should I soak block or spray block the sweater and should I block the individual pieces or wait until after it is assembled?
Thanks, trying to improve my finishing skills.
Also, should I use the mattress stitch to sew together?
Appreciate the advice.

I don’t knit sweaters in pieces, but from people who do it seems blocking the pieces separately to size makes it much easier to seam. There is often a schematic on the pattern that tell you the measurements of pieces.

Mattress stitch is most often used for seaming. Shoulders are are often a 3 needle bind off to provide stability. I’m not sure about sleeves so hopefully someone can answer that.

I agree with Jan, block in pieces. You could block after you seam the raglan sleeves to the back and front but I find it neater to block all the pieces separately and then seam. You can either wash, remove most of the moisture and block or dry block and then spray. Either works well.

Thank you!

Appreciate the response. Thank you!