I have this trouble with my Angel Tarot, and since the deck is not only bid, but gilted in silver edging, it feels kind of sharp. o_o
I've gotten a method of doing this, take a card from the top, lay it face down. Then from the bottom, then from the top, then from the bottom. This mixes things pretty well. If you're starting from a new deck though, you can divide it into several piles and shuffle them separately first, its easier that way, less unwieldy, then just rifle each shuffled pile into each other.
Lots of ways to shuffle a big deck. I sympathize, my hands are pretty small. I had problems with piano playing because I couldn't reach the widest chord with my hands, making lessons almost impossible.