I need help expanding my cabinets! Determined to DIY it!

There really isn't any way to make the existing wall cabinets deeper without losing the integrity of the cabinet itself. You can't just add wood panels to the cabinets. Also deeper cabinets have a thicker back and must be screwed into studs to carry the extra weight. On the taller cabinet, you can build a box out of cabinet grade plywood sized to the cabinet dimensions and stack it on top of the existing cabinet. Make it about 1" shorter than the ceiling height so it can slide in. Crown molding will cover the gap.

A friend moved her cabinets up and added an open shelf on the bottom for extra storage. I have no idea how to make cabinets deeper.

to make the cabinets deeper, you will have to build new ones. To make them taller you could run some type of pipe, drill holes into blocks of wood and the end could fit in the blocks creating a front with full wood sides on the top but that requires a lot of cleaning. If it's a lot of space between the tops of cabinets and ceiling, you could possibly build a cabinet to fit the space, perhaps use French cleats to hold them up

There is a lady in Alaska, her blog is call Anna White. She has built all kinds of things including kitchen cabinets. She has free plans on her site. I have built a ton of her stuff, and her plans are easy and they always work.

It would cost you less to replace with new pre-fab cabinets the depth you want rather than increasing. Also you will have to look at the wall space allowance (like....are the cabin-ates on a wall by a doorway? You will need to also replace the bottom ones). As for adding to the top that is quite easy. If there's not a lot room, you can still make it and store rarely used items like (baking tins, cookie sheets, trays, extra supply of foil paper, saran wrap, etc.). Don't forget you'll also need to replace the counter top.