People probably won't like me for this answer, but this is what I do all the time. Probably not the correct thing to do, but whatever, it's what I do & it always works.
When I do street readings, unless people want to pay me a lot more, I do 3 card spreads (for purposes of time and because 10 cards just tend to blow away). What the positions mean depend on the question (i.e., yes or no question, relationship question, past present & future, etc). Sometimes there's that *one* troubling card, the card the sitter has no idea what it's there for. When this happens, I say, well, let's see if there are any more clues as to why you got that card, and I draw a significator card to lay with that one to kind of go deeper into the meaning of why they got that card. On very rare occasions I've even drawn two significators to go along with the same card. If it still doesn't ring true I just tell the person I'm not getting anything, possibly because it's either unknown at this time or too much is pending, so ask another question.