Several have mentioned 1st and 3rd steal situations. My observation is that as you move up in age you see (16u-18u) fewer, not more, teams who use special 1st and 3rd defensive plays. You either have a catcher who can discourage that attempted steal of 2nd or you don't. The other team either wants to be aggressive or they don't. If your catcher can't make a very competitive play regardless of a runner's speed at least 75% of the time then you probably have no business trying to defend that steal or making a trick play. Let them have it, keep the runner on 3rd, and move on. On the other hand, if you have a consistently good catcher and the situation is right (for me it's 0 or 2 outs with an average or below average runner at 1st) go for it. Don't mess with a trick play just try to get the out. You'll be amazed how often the runner on 3rd is either caught flat-footed or assumes there must be a trick and doesn't go home or breaks late enough to try and make a play there as well. I just haven't seen the typical 1st and 3rd cut-off or trick plays work often enough to justify practicing them. I'm curious if others have though.
I'm with you. I'm of the mind practice most what happens in your games. That's going to depend on the level you coach. I'm not saying don't practice 1st and 3rds or bunt defenses, just spend the most time on the things you're going to see most. I'm a HS Varsity HC. We spend a few days early in the year on our 1st and 3rd calls and rundowns until we have them, but after that, we hit them every now and then to keep fresh, but it's not at all close to daily. In the last few years, we just haven't been in a ton of those situations. But when they do happen, we know what our priority is and how to handle the situation.
When it comes to 1st & 3rds, we throw through or 2B cuts it off, we're not trying to trick anyone. Score and situation determine which. In our league and area, no-one is getting an out at 3rd with a quick throw. Teams are too well coached. Majority of the time, our priority is runner at 3. 2B has the option to read the play and cut even if we call a throw through if she feels she has a "better than good" chance to get the runner between 3 and home. Again, score and situation plays a big factor.
One thing about situational practice, don't always tell them what to do. Let them figure it out. Coach, yes...but speak quickly and only when you need to. Let the team huddle and talk it out. Situational IQ is one of the hardest things for teams to learn, but when you over coach and always make the calls, they don't learn to react, they learn to do what you say. They need to learn to understand situations, not always follow directions.