Bear with me, I'm not the mechanical keyboard wizard you should blindly listen to, not in the least. Still, mistakes were made and also good things happened while building my two keyboards. So, let's just pile things up:

Try to stick with layouts as close as possible to standard

Depending on what key caps you will get later on — your taste can change drastically over time — you should invest some time answering these questions:

• Do I really need a split-space layout? You will usually need to buy additional so-called "extras" that increase total cost of your new keycaps. Sometimes, the required 2.25u/2.75u space bar key caps are hard to find or do not exist for a specific key set
• Decide if you want a 2u or 2.25u left Shift. Same reason as above

If you enter a key cap group buy, rather buy more kits than you think you might need

Here I'm referring to the "extensions", "40s", "ISO", "novelties", "space bar" etc. kits. Why? Because you switched from traditional to ortholinear. Or, suddenly you like split spacebar or vice-versa. It's so frustrating to have to hunt down single key caps, as it's often overpriced and hard to arrange deals.

Think twice before you buy a PCB without ESD protection

I own two DZ60 PCBs, and one of it has some fried keys that suddenly appeared after I moved the keyboard to the office once. I forgot that the whole office building has weird electrostatic discharges when you for example touch stair handles. So, better chose a PCB which has ESD protection built in.

If you live in western Europe, plan your orders and buy some stock

Western Europe is often an expensive destination to ship packages to. It's very frustrating to reorder additional items or correct a bad purchase.

Example needed?

• You will most probably never want to replace your stabilizers once everything is soldered. So go all-in and buy the best you can afford right from start
• Switch films: so cheap, yet so easy to forget that they exist

Buy a switch tester and many different switches

There's a big variety in switches available. From tactile to linear, from heavy to light operating force. There's a switch for everyone. With some kind of switch tester you may rule out some switches, which increases the likelyhood to buy switches that you enjoy typing on. Note: do not take the sound a switch does for granted. It might sound quite different in a closed case, with or without additional dampening (mat, switch films) and also depends on key cap profile (SA vs. Cherry for example).