Why you struggle with “Look Ahead”
Look-ahead: The act of finding, tracking, or even planning what your next step will be, whether it’s having a complete picture of what the next case will be in its entirety before you finish executing the case you’re currently solving, or noting qualities of what the case could be (For example, knowing that the two pieces will be stuck together in the U layer)
Said simply, it's actively focusing on the next step, while your hands execute the current step with muscle memory
Why do cubers often struggle with look-ahead?
Look ahead is one of those topics often talked about by YouCubers of various skill levels, usually with a lot of emphasis on the fact that "look-ahead is a mindset broo, you gotta wait for it to CLICK!"
Usually it’s talked about in the context of F2L, and is what I’ll be using for example sake, but all of the advice I’m going can easily apply to things like 4x4-7x7 centers and edges, and even Cross to some extent (algorithmic steps like OLL>PLL are a bit different)
Anyways, you'll hear them say that the reason you pause/have bad look ahead is because "you don't do enough slow turning practice" or "you turn too fast" or the classic suggestion of doing more "metronome practice!"
As much as those often suggested pieces of advice make me want to roll my eyes, I think sometimes that can be helpful advice when the right pieces of information are in place (which I will be covering shortly)
For the vast majority of cubers however, it's an entirely incorrect suggestion for advice because, like I said, the important pieces of information on HOW to look ahead aren’t there, and often aren’t explained properly by the aforementioned YouCubers
Usually it leads to people turning fast-then-slow-then-fast, which isn't exactly how fast times look when you watch Feliks and Max, who, believe it or not, pause sometimes
Anyways... I don't blame these YouCubers for pandering this advice in the slightest, but it’s unfortunate that the most mainstream advice on Look Ahead has historically been the least important aspects of it
And again, it can be good advice in the right context. However, it’s rare that I see this advice lead to improved look-ahead
So, if slow turning, listening to a metronome to the point of borderline insanity, and “just getting used to it and figuring it out” isn’t an appropriate starting point, then what is?
In my humble opinion, poor look-ahead is a symptom of inefficiencies in F2L
Plainly put, if your F2L is a mess of intuitive solutions that aren’t the best solutions you could be using, mixed in with not even knowing your cases on a case my case basis, then look ahead is the LAST thing you should be concerned about until the inefficiencies are addressed
You can work on look ahead if you want because your favourite YouCuber thinks it’s like totally really cool and stuff, but I promise you it’s not going to get you anywhere and certainly won’t make you much faster before you hit your next plateau
Getting more into the specifics of F2L inefficiencies, there's a lot of possibilities
By far the most important of them are
Your F2L solutions are too "intuitive" and you can't look at two F2L pieces, close your eyes, and then solve them with utmost confidence that they'll be inserted correctly. You can hypothetically solve this by learning your solutions, but if you’re keeping it “too intuitive”, then…
…even though you can solve some pairs with that level of confidence, your solutions are so bad that you end up moving all sorts of pieces around the cube from multiple slots and it's a chaotic mess to track anything.
A good rule of thumb is that 80% of your F2L pairs should be around 7-8 moves long, with the remaining 20% being either lucky 3-4 move inserts, or slightly unlucky but still fast 11-12 movers
If this is your problem, learn new good stuff from the algdb.net F2L section and eventually pick up tricks from studying top cuber reconstructions on cubesolv.es. The less efficient your F2L is, the more moves you’ll have to do without looking at the pair you’re currently solving, which is obviously harder
Even if your solutions and confidence are on point, your y/y' rotation choices aren't on point and you're constantly filling up the front and right slots instead of making the effort to fill your main "blind-spot" slots (BL is the worst slot to have unsolved, followed by BR, then FL, then FR. If you're a left dominant solver then it would be the L/R reflection of the slots I just described)
Solving this issue is just a matter of making better decisions with your y and y' rotations. Whenever you have a y or a y' rotation you HAVE to do, there's almost always a correct answer from a look ahead standpoint
Eventually, you’ll want to stop prioritizing look ahead with your rotations and instead always rotate in the way that gives you a faster angle to execute from (for example, front slots usually allow for higher TPS and less regrips), but this is only something to keep in mind once look ahead isn’t an issue for you
Now, if any of that sounds like how you currently solve 3x3 F2L, like I said before, my suggestion would be to not even worry about look ahead and instead address the roots of your inefficiencies at the micro level
If you're efficient enough, then working on the mindset switch where you're not looking at what you're currently solving, and instead looking around the cube for new information is what you should be doing (and if you want to start by doing slow turning for a day or two to get the hand of not looking at the pairs you’re currently solving, that’s perfectly fine)
Oh, and don't strive for pauseless solves
Seriously
You're going to have solves where pieces get stuck in certain blind-spots or where a brief pause is useful in order to take advantage of something that will save you turns
You can pause during F2L and still have good look-ahead
Inversely, you can have F2L where you "never pause", but because your turning is fast-then-slow-then-fast, your look-ahead is garbage as far as I'm concerned
Bottom line, screw metronome practice and whoever though it was a good idea in the first place
Don’t look at the pieces you’re solving while you’re solving them
And if you can’t do that
Then you know you have work to do