Its easy to get too much stuff, doesn't matter if its gear or tools or something else. The trick is to keep organized. Don't fall into the trap of running out and buying a bunch of stuff or grabbing whatever Walmart has on sale, in the long run you will end up with a bunch of crap that gets misplaced, lost, or broken.

Start out by taking an inventory of what you have. I created a few spreadsheets, one for my EDCm one for my Bob, one for the kit in my truck, one for the gear in my garage, etc. You will find out that you have a lot more than you thought you did once you list it all down somewhere.

Then categorize all your items, I took a bunch of different "10 essentials" lists and consolidated them down to a basic essentials list and then grouped/categorized all my gear accordingly. Then I was able to count the gear for each category and see if I had too much of one and not enough of another.

Then decide on how you will store/carry all that gear. I make it a rule that before I buy something it has to have a place, be it a bag, box, shelf, etc if I don't know where to put it then it doesn't get purchased. See the shiny new knife, hmm, where can this go in my bob, maybe the side pocket, check the spreadsheet, I have three knives in tha bob already do I need another, maybe this can replace two of the others, if so then I'll buy it, if not then I pass.

So by my organizational scheme every item must justify its self in how it fits into the essentials and plan I have set forth and where it will be kept. This prevents me from buying a bunch of gear and then having to find somewhere to put it and prevents me from buying a bunch of stuff that I either have plenty of or don't need.

My essentials spreadsheet is sort of a master plan besides listing the essential groups of gear I list ideas and a direction I want to go which helps with future gear purchases.