I like using bunches of cards with the same cost. Say, several 3-cost cards, a few 6-cost cards and a couple of 8-cost cards.
That way the choices are a bit trickier and you won't always spend whatever quid you've got to buy the most expensive thing.
The drawback is that you'll almost always know how much quid you want to spend, which makes the question of what to summon a bit more trivial.
Yeah I would like to see the cards he is using.