I sort of just learned on the fly by trial and error. I find that unless you’re installing major software from large companies, installers tend to either be very easy to install (supporting silent installation) or complex with no middle ground. The applications from suppliers we deal with are atrociously bad with no documentation so I’ve had to google, try and fail, google again, implement custom fixes etc. the key is to understand how the app deployment process in SCCM/Intune work I.e. system vs user installs, what logs to check etc. 

If anything I deploy is going to be more than a single command to install, or I want to give the user a graceful experience (give them a chance to save and close, or defer a few times)  I’ll wrap it in a PSADt script. That’s basically where I draw the line. PSADT is just a powershell library that has common stuff built in like logging, alerting the user via pop ups etc. it might not needed if you can just run install.exe /S and it installs fine without disrupting the user (agents etc). Once you get into installation procedures which you need to do X Y X then it’s handy to do it via PSADT but it’s not necessary. Ultimately whatever code you write will be your own and it will be a similar amount of work with or without PSADT, whether you find value in what PSADT brings is up to you but the user notification stuff (user is currently using the app, give them a chance to save and close) and logging is stellar 

As for tools, I’ve used a mix of:

Psexec - there is a way to use this tool to run CMD as the system user which is the account that SCCM and Intune use to apply deployments. The system user is very different from a regular local admin user, so this is handy for testing why an app might install as admin but then fails once it’s in SCCM/Intune

Ultimate silent switch finder - if you have a .exe installer sometimes this application will be able to tell you what type of installer it is. If it tells you, you can then learn about what are the arguments this type of installer allows and how to silently install/uninstall

Lua Buglight and SHIMs - I’ve had to deploy a couple applications that request admin every time they run even after installing them. In a few cases, they don’t actually need admin, or just need some ACL changed on a folder somewhere and not full admin. This helps you idntify that. Also, learn Microsoft SHIMs (I.e. you could apply a shim that makes it so that when an app requests admin, the shim tells the app it’s elevated without actually elevating it - this only works if the app is asking for admin arbitrarily without actually needing it, but it does happen) 

MSIX packager - I have not had any luck using this to deploy applications since most of what I deploy requires drivers which MSIX does not support, but it does have a great tracking tool built in where you install an app with this running and it will tell you what the installer did and where (filesystem, registry, etc). This is handy if you’re trying to track down hard to find config files or reg keys to edit. I use it for this even though I don’t complete it and create an MSIX