It depends on the purpose of what you're looking into and who it is you're contacting.
Most communicate with us daily and we're not aware of it. Some would rather send messengers or sentinels to do the communicating for them and then there are ones you never want contact, for any reason.
If you're looking for favor, blessing, or assistance in the craft, setting up a sacred space for them to come to meet, is favorable. For other needs, focusing on them and sending your thoughts to them, essentially prayer, works well enough, but you must be patient and seek the answer actively. They may not answer as directly as you'd like.