It really doesn't matter that much, for us batch spargers especially. One thing you do need to understand is the temperature effects of using more or less water in mash vs. sparge. I typically use anywhere from 1.3 to 1.75 qt water per lb malt in the mash. At end of mash I like to add at least a couple quarts of boiling water for a pseudo "mashout" which is really just to slightly reduce the viscosity more than anything else. Then take first running, then add however many gallons hot ~190 F water that will give me the total preboil volume that I want. I have a spreadsheet to calculate all this stuff, volumes & temperatures. Without software, you can only get good at this through experience in doing the same things over and over. With software (or a spreadsheet), you can fiddle around as much as you like.
Exceptions:
For very high gravity beers (like 1.085 or more), I prefer to mash in with as little as 0.9 qt/lb, then batch sparge twice to maximize efficiency. This way, instead of getting only like 55% efficiency, I can still hit the 70s on efficiency, or once or twice I think I even got 80-85%. This is only possible with a super thick mash, large sparge, and longer boiloff time, like 2 or 2.5 hours instead of just 1 hour.
Then for very small beers around like 1.040, I might BIAB at up to 3 qt/lb, don't squeeze the bag, and skip a sparge entirely.
Ask 100 homebrewers what to do, and we'll give you 100 different answers. In the end, it's all good. Do whatever you like. You'll make good beer any way you do it. It really just doesn't matter. Learn by doing. Do it your own way. It'll be great.