I always use the 'garter stitch' selvage edge. It's worked as a "knit stitch" on both WS and RS.
I only use mattress seaming.
My only tidbit of advice for a knitter that is new to 'garment' knitting: follow the pattern. Don't take short cuts. Don't knit "in the round" to avoid seaming. Don't knit the fronts and back as one piece to avoid seaming, if the pattern says to knit the Fronts and Back as separates. Follow directions.
Swatch. Don't take short cuts in this department.
Block your pieces.
EG: I blocked the 7 pieces of my YANK Peacoat. Tonight, I seamed the shoulders, seamed the sides, and seamed the sleeves, cuz the pattern gave that sequence. But now, before I seam the sleeves into the coat, I'm once again blocking. I've laid out the coat (the Fronts and Back are seamed at the sides and shoulders) flat, and I've laid soppy wet terry cloths onto the side seams. This will flatten them more, and make a more professional 'appearance'.
Anyway, if you are a Raveler, take a peek in at my KAL's over at Ravelry. I've included dozens (maybe more) of garment knitting tips. True, some of them are specific to the project, but many of them are applicable to any knitted garment!
Clasica Coat KAL
Tweedy Aran KAL
The Knitalongs are very well organized for each subject pertaining to the project, so if you are looking for (example) seaming tips, click on the subject: SEAMING.
And thanks for the compliment, in asking my advice for anything! I appreciate your kind words, and your confidence in my knitting. :hug: