Similar to the icepick, I have a woodworking scratch awl that is very keenly pointed and punches through leather well. Modifing a more blunt profile with a file and some stones would work too. I just lay the leather flat on a board and push the awl through into the board.
For sewing, if you don't know what one is, look into a sewing palm. It is like a fingerless glove with an armored palm that has a lead disk with dimples in it that you can use to push on the butt of heavy needles. They are found in marine stores, used to sew heavy canvas, etc. They come in right or left hand.
A cake of beeswax to pull the thread across helps sometimes. For thread, I like recycling 90lb test, braided dacron fishing line, that I take off my halibut saltwater reel at the end of the season; you can buy new in many colors at a sportfishing store. It is very thin for its strength, pulls easily through the leather, resists abrasion, does not rot, and holds knots well.