If you need to gather a section for a sleeve or whatever, and you are frustrated with trying to pull a gathering thread, the easiest way is to zig zag stitch over a piece of yarn or crochet cotton. PUll up the gathers and secure. I have even seen elastic attached this way on little girls' dresses sleeves.
One tool I wouldnt do without in my sewing room or my knitting basket is a couple of old fashioned diaper pins. The best ones are the ones with a plain closure, instead of a duck or something, but any will do. These are perfect for threading elastic through a casing, holding pattern pieces in place, attaching sections before sewing, and wonderful for stitch holders for knitting or stitch markers. I also like to use them to pin up my husbands pants when he tries them on for me to hem.
Instead of hemming the toddlers'pants, insert a narrow piece of elastic through the hem like a casing and pull it till the pants gather at the ankle like sweatpants, but not too tight. Secure. This saves time and keeps you from having to let out and rehem as he or she grows.
To keep freshly pressed fabrics and garments from getting wrinkled, allow them to rest and cool down on the ironing board for a couple of minutes before moving them. If you are in a hurry or just impatient, use a fan directed at the ironing board to cool down the fabric and set the press.