I am a little confused by your question. All the things that you listed as not being applicable to real life scenarios are what you call short term memory boosters. Short term memory (0-30 seconds), intermediate term memory (30-120 seconds) and long term memory ( 2 minutes +…) are a function of the amount and kind of attention you give to the target memory experience.
Short term memory = just pay attention in the first place. That is it. That is all that is required to remember something for up to thirty seconds.
Intermediate memory = do something to transport the item from those physical parts of the brain where attention is managed to those parts of the brain where memory is invoked. Because the attention part of the brain has a limited amount of space and energy to deal with its function, it is selective in what it keeps for the maximum amount of time. Current thinking is that short term memory holds about two hundred constantly rotating bits of information and another four hundred are available for inspection at any given moment. There are management techniques available to consciously direct the transfer/conversion process.
Long term memory = do something to attach the newly loaded intermediate memory into the massive, physical connectome that constitutes what we call long term.
Just like there are physical exercises that will increase the size and capacity of your biceps, there are exercises that will increase a specific memory circuit in terms of the circuits physical characteristics and capacity.
If you load the intermediate memory into long term and just leave it there without some other factor involved it will start to degrade within hours. Some so called short term memory enhancers will by themselves allow the intermediate memory to disappear from its temporary long term position quickly. Some action needs to be done to prevent that from happening.
If you truly want to enhance the transport of intermediate memories into long term, the practices that you dismiss are the tools to do it. Card drills, number sequences etc are ways to improve and hone your ability to rapidly and reliably move memories to where you want them Those card remembering practice sessions are intended to load and retain the card order for only a very short period of time. No one intends to remember the card order for the next few years.
But if you can’t move that memory where you want with ease you will not be any good at long term memory. These memory champs are showing how much you can get control of the process. You can get so good it looks like a trick or magic to the uninitiated.
However, your psych student friend is correct. It is vital that you increase your actual short term memory. If you don’t pay attention in the first place to what it is that you were hoping to remember, it is impossible to do anything about remembering it. If you didn’t really pay attention to what someone’s name is, nothing will bring it back later. However, all the tricks to move memories around to your liking force you to pay attention in the short term interval. All those tricks say…after you have really paid attention, do this, or that, or that.
To list resources it is necessary to know what it is you really want. Somehow, I don’t think you are much interested in different meditation or yoga techniques which will result in improving your short term memory because they enhance your ability to be in the present and pay attention. Increasing your ability to be aware of yourself and your relation to your surroundings is probably the best real world application of your energy you could do. But few people are thinking about that sort of thing when trying to do what they call improving their memory.