What works the best for me is the Klein 1006 crimper. It's a non-insulating crimper that I use for insulated crimps. They make very solid crimps because of the narrow head and the "U" shaped crimping pattern which makes less effort to crimp than to use any other types. I've had numerous, and I mean NUMEROUS challenges by other installers who think their ratcheting and other types of crimpers make better, secure crimps to no avail. I always bet on lunch and to this day, never have lost. To do a challenge, a butt connector is used and we crimp our side to a wire which gets pulled apart until it gives. It's a lost art of crimping connectors by feel and I "know" when I've reached optimum pressure.
3M terminals are used for interior and dry locations. Solder and adhesive lined heat shrink gets used in wet environments if I can't avoid splices. I always use drip loops with the connections on top of the loop. Quick disconnect terminals are carefully located into dryer areas and dielectric grease is always used.