Hi Andy,
I built my first kit (Crack) earlier this year so know exactly where you're coming from.
Watched quite a few YouTube videos before starting and I think a lot must be down to what people are used to or find suits them best.
My advice can only be based on what I did and which worked for me. I bought an iron with a selection of tips and did a few practice connections where it doesn't matter.
You soon get a good feel for how quickly the solder melts and for it to flow. And flow is not just an expression, the solder really does flow.
The join needs to be well heated so a good iron contact required which may be easier with a larger surface area (larger tip) when starting out.
However, I was concerned about having to leave the iron in place too long for fear of damaging components. I still don't know enough to be sure of how hot some components can get.
I started with a medium sized pointed tip but have now ended up using the smallest pointed tip I have for most things. At same time, temperature I set on the iron has increased.
Having some solder already on the iron helps, now takes a few seconds (3-5) to get a good connection.
Practice and find what works for you, though I did find things easier with a smaller tip.
Hope this helps - I am sure there may be other more experience builders that can give tips (pun intended) if you need.
Regards
Chris