The paintless guy who worked on my car, didn't use pullers or suction cups, but was very skilled with long rods which were bent just right and with small spade ends, to reach inside the bodywork and slowly work the dent out by twisting the long rod. He slowly worked that dent right out, using a mirror on the outside to be able to have a sight line along the outside metal to look for any wavers, etc.
Large dents would require the puller or suction cup routine to get the major deflection out first.
89 Milano (wife's daily driver since 1989)
91 164S (my daily driver since 1994)
94 164LS (~Q) (trip Alfa since 2000)
72 Morgan 27 (water time since 1976)
previously owned since 1964:
62 Morris MiniMinor 850, 67 Austin 1275 Cooper S (Downton 3/4 race), 64 Giulia Sprint GT (1st red one made), 72 Fiat 128 Sedan, 75 Alfetta Sedan, 78 Alfetta Sedan, 78 GTV, 81 GTV6, 86 GTV6