Having been mentioned twice in this thread, maybe I should weigh in a bit...
- whilst I can see the appeal of the tiny case - it'll fit in your handbag (or purse, if you're American) and they're on the cheaper end of cases - they're not really very good for beginners...
beginners need space to add modules to find out what they actually want and the modules that they really need to support them... part of the appeal of modular is that you can reconfigure your synth based upon how you patch it and having (over time) the ability to add 20 modules or so is useful as this will open up a myriad of possibilities in terms of patching which cannot be achieved with the contents of this rack... not buying a decent sized case also leads to the slippery slope of more cases - I should know I strated with a small (6u 72hp) case and having nearly filled it within 6 months bought a mantis - so I could fit maths in... I now have 8 cases...
also some small cases are quite shallow and won't fit some modules in (2hp, for example, as the pcbs are perpendicular to the panel and mot parallel) which can result in people using standoffs which is all very well until you manage to stick a patch cable in hte side and short something out...
go for a mantis (still inexpensive) or one of the intellijel performance cases if you must be tied into unnecessary things like output modules and midi in) they are still quite portable - I've taken my mantis on planes, trains and buses many many times and not had any issues
if you absolutely must have a tiny case - start with a bigger one work out what modules you absolutely must have in it and then buy the smallest case you can to house those - buy only once you actually know what you are doing...
MylarMelodies and others who show off tiny systems on YouTube are often only using them to highlight single modules or patches... having taken a few modules from their bigger case(s) and will then re-arrange them before the next video... and whilst it is possible to build a 'techno groove box in 62hp' it's probably not going to keep you interested for more than a few months...
work out the modules you want and then work out what you need to support them - and leave at least 20% if not more space and then find a case that can house those modules - and can power the extra space when filled - I always estimate 10mA per hp per rail - and then allow at least 20% headroom on top of that...
utilities, utilities, utilities... see my signature for some hints, but I'm not really talking about O&C or Disting EX - which can be useful but tend to end up being left as one thing when a dedicated module probably does it better* - I'm talking more about really basic things like vcas (you may or may not need a lot of these), switches, mults, attenuators, attenuverters, logic, clock dividers, and mixers... and whilst these can be inexpensive (doepfer and ladik, for example) they do take up space...
- my disting mk4 was used almost exclusively as a tape delay for years
- ergonomics... small modules with tiny knobs do not make a pleasant playing field - not only do they need to be separated (you've managed to do this quite well) but they also need to be not next to other modules that either have jacks next to them that you will use or knobs - as you will not be able to get to the knobs to adjust them once patched without resorting to tweezers - which can be frustrating, to say the least
"some of the best base-level info to remember can be found in Jim's sigfile" @Lugia
Utility modules are the dull polish that makes the shiny modules actually shine!!!
sound sources < sound modifiers < modulation sources < utilities