What are some effective methods to avoid wasting your soldiers' time as a platoon leader?

Sir - there is very little that you will have control over once you hit your unit. Many things that waste Soldiers time come down from Battalion or Brigade, and your Company Commanders/XO's/1SG's are reacting to taskings and last minute shit themselves.

The best advice I can give you is this - May you have the strength to change the things you can change, the intelligence to discern what you cannot change, and the wisdom to tell the difference between the two.

You as the PL don't have a lot of effect on their daily schedule but you do have the ability to negatively effect it. Don't try to fill all the white space on the training calendar. Don't issue tasks at the end of the day. We know it's only because you're getting tasked at 1600, but you need to push back when possible in situations where it's not critical. Ensure the Squad leaders and Team leaders are pushing down the information to the lowest level by performing spot checks and brief backs with the lowest personnel. You'd be surprised how often the bottom private has no clue what's going on or why and that can be frustrating

Congratulations, you are a first line leader! You need to decide how your unit gets the work done and to what standard. Listen to your NCOs but know you are the standard keeper and must hold your yourself, your NCO leadership and your soldiers to the same standards. Getting the work done while having a great attitude and setting a leadership tone for this type of environment is critical. God Speed.

Try to be as proactive as possible to eliminate the wasted wait. That's about all I can say. BPT not be able to do this as much as you'd like, though.

L-T, for starters, kudos to you for even being aware enough to think about this. Now, if you notice, most of the responses here are from seasoned NCOs who likely have lots of time training troops. That's where you should be looking for your answers. I'd encourage you, if you haven't already, to have a meeting with your platoon leadership (platoon sergeant, et al) and then explain to them that you want to help them maximize their effectiveness and manage their time, especially when you have to pivot to the latest hot tasking that comes down from yonder. They will let you know (if they are worth their weight), trust me. But the first step is caring (you can't teach that) and you've got that covered. Ask them what they need and then move out to support them, but I bet your noncoms have all sorts of ideas on how not to waste time. Remaining semper Gumby is key. Soldiers will take their cues from the unit's leadership. If you and your leaders are resourceful and creative, you will do fine. For what it is worth, we always had junior NCOs on standby to teach an ad hoc class to fill gaps. Any perishable skill or military hack is a good topic.

As a “baby” LT, try to learn from your Joes. It’s motivating to see my LT actually try to learn the equipment and their soldiers. My personal point of view though.

A lot of great comments by others!

A deviation on the “hip pocket training” for situations like this.

On occasion, rather cover alternate training, I would delve into a subject that would be difficult to get on the training schedule, or have a Q&A session. I remember one “alternate” class was on personal finances which was often the bane of junior enlisted (this was way before the internet). Another was how to file taxes. A question I still remember from one of our short Q&A sessions. A junior SP/4 asked the platoon sergeant what made him stick around versus getting out.

-anticipate tasks that need to be done. If you have something you know will be a due out in two weeks start it now so there is not a big rush to do it the day before. (Things like inventories and gear prep)
-have hip pocket training always ready to go. Use your NCOs to help facilitate training. I don't know what kind of officer you are or the troops under you but we will use mine as an example. *Bam you notice white space* break out the hand held detectors, robots or chemical detectors and give a quick class, pmcs, and get to using them. It can even be proposed as having them teach you. You are a butter bar they don't expect you to know anything.
-plan, plan ,plan know what is going on, where white space is likely to be, what upcoming training is going to be an facilitate training that will give them a solid foundation for upcoming training.
-seek out other units to cross train with especially if you would work with them deployed.... like medics you can never have too much training on how to save the guys around you, and how they integrate into your formation.

I could go on and on. If you end up at Fort Carson hot me up, we can do lunch and I would love to tell you how I have had my time wasted through the years and how I think it could have been better and I am always looking for cross training opportunities for my guys.

You just need to approach each day with the ability to improvise and be flexible. Nobody here will be able to hand you the magic pill or the secret formula that fixes "hurry up/wait" or stagnant delays. Just go forward knowing the plan of the day and execute it while cutting out any drama or BS. Go forward trying to help your troops, complete the mission and reduce/limit the fluff you will be fine. Don't get complacent and maintain a proactive approach while also leaning on your NCO's. They will generally have good ideas and just need a nudge or maybe just the opportunity to surprise you. Don't try to reinvent the wheel but look at ways to improve it.

Make everyone a valued member of the team and instill importance in their role no matter mundane it might be. Everyone wants to be important and valued, and if you can manage that you’ll be an impactful leader. Best of luck.