Vouchers are a great gift idea for everyone!
It allows your friend to choose what they want, and when they want to use it. I always allow a 3 month expiry date to make sure they use the Voucher promptly within this time frame.
With a gift of a $70 voucher, I usually offer a 30minute Tarot reading which includes some Numerology and Astrology to look at the big picture coupled with more indepth information using the Tarot cards.
They also have choice to upgrade and then they can mix and match products and services that I offer.