mmmm... Must have's a bit opinionated. I have a few favorites but there's not much I MUST have in my arsenal that will prevent me from accepting a job. however...
I must have the follow to effective do my job
steel wool
any OTC soap. ( I currently use palmolive dish soap mostly... gentle on the hands LOL)
Meg 105/205 are great products but if I'm out I reach for my Danase' line up's
I'm really on the new "HD protect" bandwagon. Much better than 303 and a lot cheaper when so little goes so far.
Folex. just dosen't get a better bang for the buck product for stains
clean pads dosen't matter by who.
good supply of clean MF's Dosen't matter by who.
Wax is wax regardless. I like to keep paste and liquid on hand though.
And lastly I'm still a huge fan of 3M's Ultrafina. for a nano-polish it's hard to even get close to what this does.