Just one experience was enough for me.. I used to pull a card to predict my day and it worked well. Until one day I pulled the Tower and it turned out to be a day from hell. About a dozen bad things happened that day. After that I decided I´d rather not know.
So now I do what Citrin says. I pull a card just as an advice for the day but not for any sort of prediction. I very rarely use the cards for prediction these days. Not because it doesn´t work but because it does -and I´m too much of a wimp to want to know. Advice and soul searching is fine but knowing about stuff beforehand is a different matter and has to be handled with caution.