I think the main ideas/processes have been touched on here. Sanitation/cleaning is more of the task than most expect it to be, make sure you don't lose you focus on that, but don't become to anal about it either.
Depending on the style your going for ferm temps can play a major role or not, Belgians can be a little more forgiving, if you can keep them temp in the mid to uppers 60's for the first few days then let it free rise your fine. Doing that with an IPA with the Chico strain isn't ideal, it'll work and make drinkable beer, but you'll likely get some of flavors.
Mastering is like mastering anything, is anybody really a master? Brewing beer is like cooking food, you might think you can make the best filet in the world, somebody with different tastes than you might think it's good or great but not the best. Homebrew because you want control of what YOU want not what others want. If others love it and can drink it all day, that's great for you, but everybody has different tastes don't forget this.
I have read many, many, many articles about water. Somebody on the west coast and somebody else on the East Coast of the US can make a beer following the same recipe. After it's brewed and fermented, assuming controlled ferm temps the beer will have some differences in taste if all the used is local water tha's available. Water is a HUGE part of the end product, so unless you know and can match the water profile of a beer you want to "clone" expect some differences in taste.
I'll be moving to a new house that whole house water filtration and RO water, will be interesting to learn what I need to change about the water to make a couple batches that I've been making for a few years now. Don't be overly critical, figure out what it is that you don't like in the beers you've made and focus on what thing at a time.
What styles are you trying to make, any links to recipes that you haven't been happy with? At the end of the day you need to be happy with what you're making. I find that buying some commercial beers is easier to figure out wat I want to make instead of making stuff myself, yes it's more expensive, but like most hobbies nobody will claim that home brewing will save you money.
If you want to make stouts let us know, if you're looking at IPA's let us know that, wheats, belgians, barrel aged, or chip soaked, pales, what ABV do you prefer, etc. There's a few aspects that play into all of those and over time you'll learn things that will help, what mas temps contribute to the end product, what the difference between first wort hopping does compared to normal 60 min additions, checking pH of your mash, darker styles need this checked more so that lighter styles. If you're not using dark malts and using tap water your likely fine, but still good to check to see where your're at and if you need to look into making changes.
A the end of the day if yo're getting frustrated and not happy with what you're making be willing to post what you did, the recipe, ferm temps, times, how you bottles/kegged, etc. Theres plent of people willing to help but you'll need to be able to layout your process if you want help.