Reddit mentions of Hansen Global 92000 SAE & Metric, 2-Row Socket Tray Set - 6-Pieces, Red & Grey

I am a huge fan of these.
If you don't want to spend the money on new foam you can buy cheap camp sleeping pads from Walmart. Here's my field kit / with the walmart pads.

https://www.amazon.com/gp/aw/d/B001C6NL52/ref=mp_s_a_1_3?ie=UTF8&qid=1501519580&sr=8-3&pi=AC_SX236_SY340_QL65&keywords=socket+organizer&dpPl=1&dpID=51-8Yw7rjDL&ref=plSrch

I've been using these and haven't looked back at using those cheap socket rails. Those things always pissed me off and never held sockets on very well, these plastic racks just let the sockets sit on a plastic pin and you can use them like a tray and put the whole thing in your service cart and it keeps everything handy

https://www.amazon.com/gp/aw/d/B001C6NL52

You can also buy singles, instead of the whole set.

They are called Hansen Socket Trays. I think he got his at Harbor Freight but just about anywhere that sells tools should carry them.

i've been really happy with those Hansen trays. Works great for the standard-size sockets. The problems always come when you get to the weird sockets, like swivels and spark plugs and stuff. For my swivels I just keep them on the rail they were bought with, and then I just got some plastic divider thingies from menards [edit: this one and those fit my "normal" ratchets, the extended swivels, and spark plugs. Actually in my top drawer i have two of those, and then the second one has my extensions in one pocket and then pens/lights in the lower.

https://amzn.com/B001C6NL52

I have them as well. They're the only ones I've ever owned that I actually like, and don't end up throwing away in anger.

https://www.amazon.com/Hansen-Global-Metric-Socket-Storage/dp/B001C6NL52/ref=sr_1_5 maybe?

I have these dividers and I love them. They're perfect for a large toolbox. The rest of the page shows you can buy it piecemeal if you have special needs.

Small boxes within drawers are a godsend. You can buy pre-built tool-specific ones like on the site I linked to above, but you can also find useful similar items at dollar stores.

If you use sockets, nothing beats a Hanson socket tray. (Overkill tray linked, but you can buy individuals for $10 or so. Totally worth it.)

Kudos on getting the toolbox built. More fun awaits you! :-)

Edit: Oh, I almost forgot. If you have lots of pliers, this is worth its weight in gold.

https://www.amazon.com/Hansen-Global-Metric-Socket-Storage/dp/B001C6NL52/ref=sr_1_4?ie=UTF8&qid=1517575540&sr=8-4&keywords=socket+organizer

They look like these.

http://www.amazon.com/Hansen-Global-92000-Metric-Storage/dp/B001C6NL52/ref=sr_1_1?ie=UTF8&qid=1426925670&sr=8-1&keywords=hansen+socket+tray

But $10 is a lot for a plastic tray with some numbers on it.

That's per set of 3. So you would need 2 of those sets to cover standard and metric. Looks like they're $45 right now on Amazon, thought I remembered them being a few dollars cheaper. So ok they're $5 more expensive than regular price at HF. Depending on your sales tax that makes it pretty much a wash. If the coupon works and your willing to make a couple trips then HF is a cheaper, as long as the quality is ok.

Yep. They're called Hansen trays I believe.
http://www.amazon.com/Hansen-Global-Socket-Tray-Pack/dp/B001C6NL52/ref=sr_1_1?s=hi&ie=UTF8&qid=1398258178&sr=1-1&keywords=hansen+socket+tray

You'll definitely want a set of these babies:

https://www.amazon.com/Hansen-Global-Metric-Socket-Storage/dp/B001C6NL52/ref=sr_1_1?ie=UTF8&qid=1468292113&sr=8-1&keywords=socket+organizer