I've seen some people comparing Lugh and Loki as being related to each other, and there is are similarities to use in connecting them.

But, personally, I think Odin fits with Lugh better.

1) they both are associated with ravens
2) they both have a magical spear
3) they're associated with shapeshifting and various skills

I tried to find a good discussion about their similarities in Myths and Symbols in Pagan Europe, but had no luck looking through the index.

Anyhow, Loki is closely associated with Odin in Icelandic mythology, to the point where they're basically alteregos at times. So Lugh and Odin/Loki do share many traits mythologically.