These are very good ideas, one I think every person who plays these games ought to read to get more out of Culdcept and Saga.
I have been playing Culdcept for a few years now, and have been playing Saga ever since I got it several months ago. Of your top 5 hints, I like that one about "use it or lose it".
There is a lot to be said for cards that require you to discard one to play it, but often times I have a hard time playing cards like that because I hate discarding. So most times I won't have one in my deck.
But when I DO have to do it, it can be a painful thing to consider. But lots of times you can take an account of your situation and see what needs to stay and what needs to go.
For example, if I am playing and I have lots of creatures on the board, my priority might be to protect them. So, if I have to discard, and have 3 cards to protect and 3 creatures and a weapon, I will discard a monster. Simply put, my priority is on protection at the moment, so I can afford to lose a monster.
But what if that is not an issue? If I have a lot of creatures, say 5 creatures and 2 weapons, what do I do? Well, to me, I can lose a creature, and most times I look for the weakest one... but sometimes this is relative. I might drop an offensive minded creature if I believe I can get that Wall of ice on the blue lands... it will certainly come in handy.
Every turn changes how you play, and you have to kinda be fluid in your decisions from round to round. Sometimes you have that uber creature like a Lightning Dragon that you are just dying to get on the board, but if you don't have any yellow creatures on the board, then it becomes a high priority to get at least two creatures on the board. It might come down to you deciding that maybe you got that dragon too early, and will have to discard it.
Sometimes the cards don't fall right. I played a game the other day with a red deck and it seemed like all my creatures were put at the end of my book, and I got a Chimera in my hand. I can't play that until I first have another red creature,so all I could do was hold it in my hand, and discard a weapon or armor if I had too many. Any spells I got like haste or mana I tried to hold on as long as I could, but if I had to discard the next turn, i went ahead and burned them.
It's not easy to discard, but like you said, sometimes you gotta use them or you will lose them. Thanks for all your tips, they are great.