As always BigBill gives us great advice...dittos on the plastic or clay pots.
I use mostly clay pots myself because they help the plants dry out faster and a good tip I learned early is to FEEL the pot and if it's cool the medium is usually still moist and what you feel is the cooling effect of evaporation of moisture in pot. If the pot is room temperature the medium is probably dry. You have to take other factors into consideration like room temperature and sunlight on the pot but this method has served me well. Also a famous orchid grower in Florida Dr. Martim Motes of Motes Orchids recommends clay pots WITHOUT holes, he says the evaporative effect is more important than the air gained by the holes in clay pots.
