Everyone wants a quick fix, to go from 0 to 60 in 3.2 seconds. The bottom line is that it takes time to learn how to brew great home-brew no matter what Tom, Dick, or Jamil tell you. Sure, there are things one can do right now that will improve their home-brews but in reality it can take years of trial-and-error before you get to that first
Holy cow! This is awesome! beer. And when you do, you will know it.
So how do you make good home-brew? Practice, patience, and developing a full understanding of what and how each ingredient and step contributes, period. No way around it.
The problem with the OP is that it is rather vague. Simply saying that you do not like your beers or that they do not compare to "mid-range" commercial examples does not help.
If you want to get rid of home-brew twang, I would suggest giving a healthy does of yeast nutrient a try.
Forget everything you think you know about brewing and make a trip to the Fermentation section of this forum. All the nuances of the brewing process are nearly non-existent until you have taken the steps to pitch the appropriate amount of yeast and are able to control your fermentation temperatures.
Purchase a small chest freezer on the cheap along with a external temp control. As long as the fridge is large enough to hold at least one carboy, every configuration (digital, et al.) is purely preference.
Do yourself the favor: It's worth whatever investment to move from hoping your brew comes out great to expecting your brew to come out great.
No one will argue that fermentation technique is not important, however, in reality it is just the latest trend. In a few years it will be conicals, or wide, shallow, kettles, or souring your beer with your own saliva, or....
Controlling fermentation temps, pitching rates, etc. can definitely up the quality of your home-brews but there is a reason why the older dudes, the gurus, the pro-brewers (outside of Jamil), do not focus on fermentation as the be-all-end-all that many claim it to be (ahem, Jamil). And yes, Palmer tends to put more of an emphasis on water profile than the others.
Pitch rates and ferm temps can improve beer, sure, but it will not save it. A beer that begins with a lame grain bill, mash schedule, or hop schedule, or the wrong water, is still going to be a lame beer no matter how much yeast was pitched or the temp controlled.
By the way, pitching calculators are based on certain assumptions that may or may not be true to your situation. And unless you are counting your own cells you have no way of knowing if you are even pitching the precise rate, anyways. The only thing that you know for certain is that your "big" starter works for you.
And while I am here, is it even possible to buy stale ingredients anymore? Okay, sure, one could buy fresh ingredients only to have them sit around the garage for a year before use, but the idea of "as fresh as possible" is a left-over from the old days when hops where stored in brown paper bags on the shelf at room temperature at the LHBS. And not to mention that, back then, it was impossible to know if your dry yeast pack or DME/LME were any good. Production technology, understanding, and know-how has come a long way since then. DME/LME are now top notch compared to 20 years ago and dry yeast is now just as good as liquid.
I'm surprised it hasn't been mention earlier, but the best thing I ever did for my beer was to buy a book. Specifically, How to Brew by John Palmer.
This guy is a homebrew legend for a reason. Easy to read, entertaining and enlightening, covering the gamut from super-noob to high level science and math... this book is a bible. After reading it, I realized how blind I was flying beforehand.
My brewing partner and I refer to John as Pope John Palmer.
When making tweaks, I always ask, what would Pope John do?
When you get through that, you can't lose with Brewing Classic Styles for recipes.
I agree.