Mini-Mill:  Get a one piece drawbar and dump the shaft with nuts that is supplied with the mill.  Put on a spring loaded spindle lock and use a 3/8 ratchet with appropriate socket to lock/unlock the drawbar.  Make yourself a small brass head hammer to thump the drawbar loose.  Mine has a 5/8 inch diameter head about 3 inches long.  When the faces get buggered I just turn it clean in the lathe.  Use collets.  They are more accurate and cost less than mill holders.  Put on at least one gooseneck light aimed at the work area, two is better.  Don't skimp on the vise.  Get a Kurt type, lock down vise.  There are several good imports available in the $85 to $100 range.  You will be sorry later if you try to go cheap.  Screwless vises, also known as toolmaker's vises and hobby vises, are very accurate and can be had for about $45 to $50.  You may have to fabricate your own hold-down locks, but they are simple to build.

Mini-Lathe:  KEEP THE WAYS CLEAN.  Use carbide cutters.  Indexable types are more versatile and cost less in the long run.  Get a live center for the tailstock.  Definitely, get the set back base for the compound slide or modify your own.  It is easily done with a milling machine.  If you are a true hobbyist, get a 4 inch, 4 jaw chuck.  Along with that chuck, get a 1 inch indicator and magnetic mount.  Fabricate a carriage lock.  There are several designs floating around.

64 1/2 inch Bandsaw:  Change out the factory blade for a bi-metal with varying tooth pitch.  I prefer a 10-14 pitch blade.  The Agressor blade from Enco cuts, at least, three times faster than the one supplied with the saw. The tension spring I-bolt, on the adjusting rod, can be replaced with a longer one and allowed to run heavier which speeds the cutting.  This is not a good idea for the factory blade.  Keep the saw clean.  When cutting large blocks of aluminum, touch the running blade with a thread-ease stick periodically.  It reduces clogging.  When a new cut is started, set the blade down, already running, on the workpiece gently.

Harbor Freight Buffer:  This is a great buffer.  It handles 8" wheels with ease, even double width. The spindles should have been threaded farther though.  Using a single wheel on each side you need to bush it up.  I made sleeves out of brass to shim out the nuts and keep them in the threaded area.  For best deal, catch this item on sale.  You will save about $20.

Shop:  Get a 6 inch digital caliper or two.  They are great.  Homier carries them for 14.95 and Harbor Freight often puts them on sale for about that.  Keep chip brushes near all machinery.  Buy good quality drill bits.  The cheapos will drift even with a pilot hole.  I highly recommend HSS, Titanium coated bits.  They are long life and do not clog easily with aluminum.  Get friendly with W-1 drill rod.  It is a very versatile tool steel that works with general purpose cutters and drills and is easily hardened.  Purchased from supply houses, such as Enco, it is lower in cost than the mild steel stocked by Lowe's or Home Depot.