I'm not a pro, I'm a software/firmware person who makes prototypes and limited run pre-production stuff. And this is not a list of what I use, it is a cautionary tale.
First of all and most importantly, DO NOT DO AS I DO!
For a long time whenever I needed hardware bits I'd buy a 100-piece box of whatever it was (6-32 x 0.5" PHP machine screws f''r instance) and ensconce it into its own little drawer. Sometimes the bulk of the screws or whatever was more than a drawer would hold so I put the remainder into a backup storage location.
Of course, after a while the little 'working' drawer emptied and I forgot that I had the backup remainder stashed away - and bought another box of whatever it was and repeated the process. So now I had two partial packages of excess hardware parts secreted away. And the process repeated. Again and again.
It worsened even more when I was at my hardware supplier's place and couldn't remember for sure what I had on hand and what I needed - and of course there was always something on sale or closeout - so the hardware assortment grew a bit more.
And worsened a bit more when I got 'orphan' screws, nuts and bolts. I didn't want to mix slotted and Phillips screws, so each got a drawer. And 'regular' hex nuts and Kep nuts.
And I also did the math and realized that 1,000 of a part at my supplier cost less than ten boxes of 100. So I started buying by the thousand.
Which wouldn't have been so bad if I had a system to remember what I had lots of and what I was almost out of. I didn't have a system. But I did have a lot of screws. And nuts. And washers. And lockwashers - internal, external and split. Plus the Kep Nuts. eek!
It is a terrible addiction. Do not go that way, yonder lurks hardware madness.
If you are starting out, buy a box of 100 of what you need, give it a logical home in a drawer and label the drawer. They are cheaper by the 100 and small stuff is pretty inexpensive and you will build up a useful supply. Keep related parts together - 6-32 with 6-32, 1/4"-20 with 1/4"-20. Resist the urge to allow opposites to attract. Put the remainder in a labeled container - bag, box, jar, and make a list of what you have and where it is. Post the list on the wall. Pick a nice big spot to put your overflow parts and label it clearly. When you think you have run out of a part because the 'working' drawer is nearing empty - check your list and see if you bought extras - or just check your backup stock FIRST before buying more.
I wish I had done that 30 years ago. I would not now have multiple drawers of the same part scattered around my rather smallish shop area. When I get some spare time I am going to organize my nuts and bolts. Or maybe just go nuts - that seems easier at this point.
Stu.
Photos are some of my 'working' drawers, plus some 'spares' and some of the 'backup' stock. Yikes!