Leather working start-up!

[Ned Buckshot]

I use a 1 inch and a 1/2 inch sanding drum chucked into my drill press.

Never had any need to try anything else!

Ned

[ST8LineLeathersmith]

Ned
 I use several diffrent size sanding drums from 1/2" up to 3"
just to chime in as per the OP
leatherworking is a craft that you can spend a fortune on tools of the craft
the more you get into the craft the more you will likely spend
if you are just making projects for personal use then you will not need a
loaded shop full of leatherworking tools and you can add to the tools as you need.
the basic things you will need to get you started will be a good sturdy work bench
a slab of marble or granite you can obtain cheaply from a supplier who sells granite or marble counter tops
you can get a sink cutout for just a few bucks or maybe even get several free just so the store can get rid of scrap pieces that is taking up floor space.
you will need a razor knife,and a stitching kit.
you will ned a rawhide or wooden mallet.
you will need a swivel knife and a set of basic tooling stamps like beveler. pear shader, veiner border stamp and you can add to your stamps as you go.
you can also improvise  for example I still cut out slotted holes with hole punches and wood working chisels I have also used a fork to mark stitch holes
you can also make some tools one of my most used tools is a stitching clamp I made myself
now once you get to the point of selling your leatherwork then it will be time to start thinking about buying a good sewing machine like a Cobra Class  or a tech sew I have narrowed it down to these two just need to sell more stuff to justify pulling the trigger however a sewing machine will cut your production time to a fraction of the time it takes to hand stitch an Item  a lock stitch will never beat a good old saddle stitch for durabiility or appearance.
and a lot of customers looking to buy custom leather products will insist on having their project hand stitched because the saddle stitch is something that cannot be duplicated with a sewing machine
another good resourse for learning basic leatherwork is youtube
check out Nigel Arnatiges channel and bruce Cheaneys channel these will direct you to other useful tutorials.
just my .02 on the subject of getting started in leatherwork.