My conworlding is like 33.3% creating new lexicon. And that lexicon is created to explain things (like historical events) I deal with in my "conworld articles", so it's mainly about etymologies and evolutionary linguistics. Due to that I'm currently focusing on protolangs, so I can derive words for various languages that now have pretty narrow and limited vocabularies.
    I distinguish, though, between 'creating lexicon' and 'padding lexicon'. To me the latter means the art of creating words to improve the appearance or enhance the size of a whole language lexicon; and by 'improve the appearance' I mean, for example, to make a conlang look more natural by having irregularities and oddities at the vocabulary level and regarding popular language and language evolution. To do that I like to torture words with sounds changes like metathesis, contraction or apheresis, among others, and I don't refuse to create almost inexplicable evolutions/derivations originated from popular/vulgar sources, as it occurs so often with natlangs. I also like to create toponyms: in part because it's necessary for my conworlding project but, again, because I need to explain almost anything in my conworld thru etymologies, from the name of a historical figure to a placename. Making toponymy, though, is also a good way to increase a lexicon's deviation ration, since it's one of the best fields to plant those irregularities and oddities I like so much1.

So basically now I'm creating a pair or three new protolangs and their respective sound changes so I can expand the lexicons of my current babylangs. Once that is perpetrated I'll put them all in the pool of congeohistory and let them interact: padded lexicon will then appear as if produced by magic elfs.