Reminisce32,
Multiple drives are the way to go. Avoid reading from and writing to the same drive at the same time.
1. Boot Drive: Laptop SSD.
I only use this for applications and autosave folders. Admittedly I use my laptop in clamshell mode at a desk 90% of the time. If you're editing on the road, you may need to use the Laptop SSD for several purposes but it's not maximal.
My understanding is that it's a bad idea to fill up spinning HDDs past a certain % as they like some headroom. SSDs might be similar in this regard so don't fill it up if you don't have to. 2TB can be overkill if you just store apps on the Boot Drive. I have about 150 apps and 512 GB has been plenty sufficient for me. I usually have about 200GB free.
However, if you will be on the road and think you will need that storage then it might be a good idea. Otherwise, you're really paying a premium for that onboard storage which would never be the best place to keep data in a multi-drive editing system which is optimal if you are working in a fixed location.
2. Cache Drive: SSD
Use a separate SSD, or OWC / Akitio / etc. RAID for your media cache which you can set up in the Preference panel of your various apps. I think the Akitio Thunderbolt 3 enclosures are out. Be careful with compatibility. Some T Bolt 3 peripherals on the market right now aren't compatible with this latest MacBook implementation of T3. There was an article on MacRumors. I think it was hubs not enclosures but consult with manufacturers before purchasing. 512GB to 1TB might be sufficient for something like Resolve, Premiere, After Effects, Photoshop, and Lightroom simultaneously. You can always clear your cache monthly.
Sandisk, Samsung are reliable.
3. Media Drive: HARDWARE HDD RAID / SSD RAID / SSD
If you only have 150 GB a month per project, you are fortunate in that you can get away with SSDs or SSD RAIDs for your media drives and go for blazing speed over storage size.
On the other hand if you will need access to old media on a rolling basis, have 4K work, multicam work, or just want to be prepared for impromptu jobs, then invest in a large Thunderbolt 3 RAID. Go for as many disks as you can afford. You're looking at >$2k-$3k for 12, 18, or 24 TB RAIDs. You'll want Hardware RAIDs not software RAIDs. Use RAID 5 mode for both speed and data protection.
Usual Suspects: Promise, Areca, LaCie, etc.
4. Project Drive: SSD /HDD
One reason to keep projects on yet another drive is redundancy. Don't keep autosave files on the same drive as your primary project files because if that drive tanks, you lose everything.
Secondly, you can also render outputs to this drive, as you wouldn't want to write to your Media 'read' drives if you don't have to.
Thirdly, you will eventually amass a lot of project files which will then be enough to slow down your boot drive if you stored it all there.
Fourthly, your data is more secure if you don't keep it on your boot drive. I don't know what kind of work you do but if you ever had to take your laptop in for repair, all your files could end up in the hands of strangers and you might not have it backed up. I also find it a little more efficient to clone stand alone drives over having stuff mixed in on a boot drive. It makes reconciling a clean 1 to 1 operation.
5. Backups: Bare Hard Drives, Toasters
If you can get a Thunderbolt 3 'toaster' drive dock from OWC, that would be the fastest most efficient solution. The current T2 dock is about $279. 150 GB a month isn't that much though and a T2 dock should chew through that in short order. Might as well wait for the new T3 toaster if it is forthcoming and similarly priced though.
Backup Hard Drives pile up, so I don't bother with enclosures. I keep nearline bare hard drives in plastic cases in a fireproof data safe for onsite storage. I keep offline bare hard drives at an offsite location which I swap out once a month with my on site backups. Remember though, when handling bare drives, always touch a metal surface to get rid of any static from your body first and never ever touch the SATA connectors.
Slower HDDs are OK for backups since they just sit in a safe 90% of the time. But since this is your archive, get the ones with the highest reliability rating on NewEgg or wherever.
I back up video media at the time of ingest and if critical, bring in my offsite backups at this time as well.
I think it's a good idea to always have 3 copies of your media on 3 separate drives at all times. All the more so when your primary storage is a RAID.
Chronosync
I use Chronosync software for backups. You can create 'custom backup templates' or you can leave a backup drive attached and it will backup on schedule. For small daily backup of project files, I actually just save to a thumb drive plugged in. I only pull archive drives out of their safe once a week or monthly.
The great thing about Chronosync is that it has many different methods for copying data since people have different ways of managing their files. And it will partition off and save folders that don't jibe so you can doublecheck them later.
It's a little confusing at first but once you test practice a few procedures the advantages and utility of each backup style will make sense.
Pathfinder
This is 3rd party file system browser overlay on top of Mac OS which I find greatly enhances productivity, file management, and backing up. It allows a great deal of customization of the interface. Of late Apple has been stripping out a lot of great features it used to have, like color labeling for folders and files. Pathfinder puts all these things back and more. I find the double-pane browser essential to reconciling backup drives with primary drives.
6. Workstation Organization
Where do all these drives go? I store all my drives on IKEA hutches or attached shelves underneath my workdesks. The more SSDs you can employ the better things will be heatwise. Sometimes I put a mini fan on the RAID When it gets hot. Same for the laptop. But it's cooler under the desk and whatever noise they generate is away from your ears. A battery backup and good surge suppressors for all these peripherals can be useful to.
Check out Adobe or Creative Cow forums for more precise hardware knowledge.