The trick for better quality low-skill soldering is:

1) Use a leaded solder with flux mixed in like the Multicore 502 [0]

2) Use more flux.

3) Use little alligator clips on adjustable arms to hold the stuff together for you so you can keep adding… yep… more flux.

4) Get some braided copper solder wick with flux in it for when you’ve finally added too much solder but it still looks terrible and you just wanna start over. After wicking away all the solder, clean up the wires with some more flux.

Oh also the flux is more toxic than the lead. Get some good ventilation so you can use more flux.

0: https://www.newark.com/multicore-loctite/c-502-99c-5c-0-7mm-...