It helps to know how to balance "negative" cards with an upbeat, positive, encouraging, or counseling slant. Merely saying,"Oops! Looks like you're in for a world of hurt, Baby! Bummer," is NOT helpful. Giving hope and guidance IS. As Pandora found out, there's always Hope no matter how many problems that box holds for you. And the cards always hold guidance too -- you just have to look for it. As dire as a querent's situation might be sometimes (and as distressing that can be for you, the reader) it is ultimately uplifting to think that you've done some good and provided some help and hope.
I try to remember the lesson of reversals: i.e., *every* card has a continuum of meanings ranging from negative to positive. That means we always can point in the direction of the positive meaning to help the querent, even when we have to explain the negative meaning too. That said, it's pretty hard to say anything unpleasant about the 10 of Cups (though I've heard and used a few variants). I also find it hard to find much that's nice about the 3 of Swords. I usually say something about how important it is for the source of pain to be revealed so you can experience it and move on. For the general health and encouragement of querents, I agree that it doesn't hurt to maintain something of a bias toward the positive. Remember, each card has a dark side and a light side.
I try so very hard to turn anything negative into something positive. Being retired from the Dental profession, you get to be very tactful in how you talk to your patients. I think the Dental office is the most feared of all medical offices for one reason or another. But I have learned to be gentle. This is what your client wants also, even though they don't say it. You know they are coming to you because they have a problem and want a solution. And for every problem we know there IS a solution. We just need to know HOW to give the feedback in a positive way. I know here we do the 3 card readings for the freereading group but when I read and I come up with a 7 of swords or a 9 of swords, I will always pull another card andput it on top of that card to see how they are going to come out of it. Most times I pull 2-3 cards and I don't wait until after I tell the client about the 7 of swords, I do it right after I do my layout. As I am going around the cards, that is when I pull the added cards to come up with something positive. There have been times when I need to pull more cards. THEN I tell the client to try to think of something positive for their negativity is all over the cards. Be sensitive to your clients' needs. It is so important.