You should add:
7. How much time do I have?
Didn't Pandolfini write a laundry list of what improvers should think about in his book "ABCs of Chess?"
There's also a shorter list that GMs go through, but I cannot remember the reference. And no, I did not mean Kotov's "Think like a GM."
(Assuming you don't have a forcing sequence, attack, or something that lets you know what to play)
What does your opponent's last move directly threaten? If that's not important -->
What is your opponent's general idea and what side (king, queen, mid) will he likely seek play on?
What is your play based on, and what area will you seek play on?
What can you directly threaten? Can your opponent ignore it? If he can, do you like the move anyway? Should your play be direct and forcing or should you be quietly improving a piece? Repeat the bold part for every move you calculate of your own until it becomes a habit, at that point you can spend your time on evaluating.
At the beginning it sounds like you ask what you should do in that extra minute at the end. I like to pretend to forget everything I just looked at and thought, and look at that one single move I plan to play as if my opponent is seeing it for the first time (blunder check) and then I look at it, by itself, and ask if that move by itself makes sense given the position (I'm not hoping my opponent will fall for something, and at the same time I genuinely think the move is good in that position). The last part makes sense to me in a way I may not be able to explain well... but it's like playing over a master game and all their moves look good or obvious... you can kind of think of it like that, checking to see if your move looks artificial or strange.
If it passes those last two tests I play the move. That's what makes sense to me right now, it's likely you'll develop something similar (that is at least a blunder check) but not the same as mine or any one else's.
Silman's How to Reassess Your Chess might be a good building block for thinking. Of course, you will probably not use his exact method.
Lev Alburt has written at least one book on how to think in chess, and I suspect more. Many people swear by Kotov's Think Like a Grandmaster, and it does contain a lot of good advice. But there is a problem. His method involves starting from a set of candidate moves. How do you know which moves they are?
My own observation is that strong players consider many less moves than weak players do because they instinctively know that those extra moves are bad for some reason, and alternatively what moves are likely to be needed in a position. Alburt's advice, if I remember correctly, was to study typical positions and to get familiar with them, the likely plans and tactics, and play for those positions.
It has also been observed that if you create random positions, ordinary players do as well in them as GMs. So there has to be something in Alburt's advice. Pattern recognition is a grandmasterly requirement.
Many people swear by Kotov's Think Like a Grandmaster, and it does contain a lot of good advice. But there is a problem. His method involves starting from a set of candidate moves. How do you know which moves they are?
A chesscafe.com review of "Studying Chess Made Easy" suggested books such as Critical Moments in Chess and Imagination in Chess to help train yourself in finding the candidate moves.
In line of these books would be Choose the Right Move by Karpov.
A series of puzzle books titled It's Your Move and Test Your Chess IQ can also help train in the choosing of the best candidate moves.
I play a lot of on the board tournaments.
recently I have started to slow down even if I am sure what I am going to play I spent another minut just to be sure it is safe.
my problem is that I don't know what I should be thinking while delaying the move.
1) first I ask myself why my opponent made his last move. and if I need to prevent something.
2) I look at my own safety.
3) I look if I can come up with some sort of plan based on the position.
in some situations I just sit and figure out where my knights would be placed and figure a way to get there.
4) I try to look for tactics / calculate / guess/ visualize
5) evaluate if my move is according to chess princples.
6) delay the move to be sure it's not a blunder.
what else should I think about? can you recommend any books what to think?
I have seen some books about what to think there they want you to make a tree of candidate moves in your mind I think that is to high level for me.
I am not looking for how to think like a GM. but how to think like a sound player.
I think if I am thinking the right thoughts I will automatically use more time. right now I need to slow meself down.
Someone 1990 rated at a tournament used 40 minutes for a move that was obvious. I think he would think about something else than the above. 40 minutes out of 2 hours is a lot.
In 7 games otb I have only lost 1½ points this season I am in 4 otb tournaments currently.