I have a Weller EC-2000 and use 2 tips. The ETA and ETB.
The ETA is used for standard component soldering, IC, resistors, capacitors, diodes, etc.
The ETB is used for heavier soldering of bigger components and larger solder pads. Transformers, triacs, heat sinks, etc.
I have been soldering for over 50 years.
Also don't forget the solder.
The BEST is called SN63, it is a 63/37 tin and lead and makes the best solder joints, this is what is used in preduction soldering. also the size of the solder wire must be considered.
"Sn63, ASTM63A, ASTM63B. Common in electronics; exceptional tinning and wetting properties, also good for stainless steel. One of most common solders. Low cost and good bonding properties. Used in both SMT and through-hole electronics. Rapidly dissolves gold and silver, not recommended for those."
I use .015 diameter but I know how to use it in all applications. You can use up to .032 but no larger for through hole soldering.
Just my 2 cents worth.