As a caster we all learn different techniques that work for us. There are no bad ones if you are getting good boolitz.

I bottom pour all, even 950 grain 50 BMG boolitz.

I use a 10 lb. 30 yr old LEE BP pot. I keep the spout clean by using my clean ingots.

All LEE pots require different setting on the dial to hold the correct temp for that alloy and mold. No two are the same. The thermostate on LEE pots is just reading the radiant heat from the pot threw to the tower that houses the Thermostat. If some have a fan blowing near there cast setup it, will require a much higher setting to reach the optimum melt temp for that alloy and mold.

Every mold is it's own character and requires different handling. For My Hard cast I use a WW alloy and usually water drop. But everything under 30 call I heat treat in the oven for hard Cast, if that is what I want.

Bullet size as dropped from the mold can be controlled some, to a point, that being the actual cavity size/ and material the mold is made from. A alloy of pure lead will drop the smallest boolits, the more tin, antimony, arsinic, and other impurities will cause/allow the boolit to cast larger. Good quality lino type will cast the largest boolits of most readily used alloys. Mold temp is also a factor here!!! The hotter a mold gets the larger it will cast, Thermo expansion. if I am water dropping frosted boolits they will average .001+ larger that a cooler mold that is dropping shiny boolits as Corey has displayed.

I use Bullplate to lube my molds, I do treat some cavities with Rapine Mold Prep as mentioned by Cayugad. Bullplate allows for the sprue to be cut while still is a semi fluid state for max temp when water dropping, love the stuff. {A google search will explain what Bullshop Bullplate is. }

Just my 14 cents.