However, a quick browse through the Monster Manual shows that goblins are armed with scimitars and short bows, not spears and spiked clubs as on the minis.
Of course, it doesn't matter, but I do like to keep them as close to the book as possible.
So after painting three of the twelve goblins as a test colour scheme I decided to convert the remaining club and spear armed goblins. I made scimitars and short swords out of the bonsium spre that the goblins were molded on.
Here is the process for making short swords; scimitars are just a slightly different shape.
Basic shape for the short sword blades.
The sprue is thick enough to make two blades.
Sliced in two to make two blades (I didn't make the halves quite equal, but for goblin blades it doesn't matter)
Two thin slices make the cross guards. the guards are drilled through, and a hole is drilled into each blade.
The guards are threaded onto a thin brass wire, super glue added to the end and the blade attached. The guard is then slid into place.
The original weapons are removed; with care the handles can serve as the pommels to the swords.
For some reason I cut the club off one of the painted goblins, never mind.
In case your'e wondering why the choice of weapon matters, in 5E goblins have a low strength, thus armed with clubs or spears they suffer a penalty to hit and damage, scimitars and short swords (finesse weapons) allow them to use their high dexterity giving them bonuses to hit and damage. Win - win (as far as the goblins are concerned anyway.