The premier long-lasting slide lubricant is Trombotine. This classic cream-style lubricant is light, spreadable, slippery but not tacky. A dab about the size of a pea will do it, half of that on each inner stocking. Rub around with your hand, most of the material on the stocking, a thin layer all the way up, none should look white, rather it's invisible when applied thinly. Then carefully work each inside tube into its outer tube to spread the lubricant. Reassemble the slide, then spray with distilled water to taste. You can add other lightweight lubricants like Slide-O-Mix on top of the Trombotine.
For new instruments, Trombotine is absolutely my go to for quieting the hand slide. Slide-O-Mix liquid lubes may need a little help and thickness until things are broken in. This is where Trombotine shines. New LT42B? Gonna need some Trombotine.
Packed in an adorable metal tube, one tube may last much of your professional career.