Having been an APA captain for about 10 years, here's the issue as I see it:
You obviously have players of widely different skill levels on a team. Some can figure things out for themselves and some can't. Some players have the ability to identify a key situation, and some don't. Some players rely on "rhythm" and some don't. Based on that I follow these guidelines:
1) For the more experienced players on my team (there is a 5 soon to be 6, a 6, and myself a 7), I will usually *ask* if they want a timeout if it looks like a key moment.
2) I try to wait until they have decided on a shot before calling time out, because if it looks like they are going to do the right thing I'd rather not waste the time out.
3) For all players, if they are about to do something disastrous, I will step in and call the time out myself. They usually appreciate this after the fact.
4) For the lower skill levels, I try to let them make their own mistakes. They often feel the need to explain to me what they were trying to do. If they take this approach, I might offer them some alternatives they could have done, or if possible, compliment them on a good idea even if they executed poorly. If they just sit down quietly, I might approach them after they have relaxed from playing their match, and try and point out some things to think about in the situation where they went wrong.
5) I try to offer assistance on the sideline when possible (when the opponent is shooting). Often I will see a safety coming up, or I know the guy is gonna miss and can predict the outcome, or I know he is going to scratch. I might tell my teammate "if you get ball in hand start with the 5 ball", or "whatever you do, don't break out his 10 ball over there. Anything else should be ok". It appears to me that my teammates appreciate this guidance.
6) Build coaching relationships that are specific to each player. As a coach, you should hopefully be able to analyze the game and capabilities of each player that you coach. This will allow you to accurately forecast the likelihood of their success with various potential shots and safeties. Also, and just as important, develop a lingo that is meaningful for you both. For example, the way I describe speed is different for each player. What is "medium soft" for one player might need to be called "the softest you can hit it" for another player. In other words, don't use your *own* definitions of speed and other variable things like that. Use the *players'* definitions. This will help a lot with communication, which is the # 1 activity in coaching.
7) Discuss with the whole team before the season starts what their goals are. If the goal is to have fun, then each person's opinion on coaching must be carefully and consistently observed. If the goal is to win, then the coach (or most knowledgeable player) must be the final word for when coaching and time outs should take place. Remember, if you are a player that relies on being in some kind of flow or groove, you need to learn how to get past that if you want to play on a successful team. If you happen to be the best player on the team, then good for you. If not, you have to learn how to pause, take advice, and reset yourself. This I think is a very useful skill generally speaking, team or no team.
Hope this helps,
KMRUNOUT