This year, I voted in 15 of the 20 categories. At the start of the reading / voting process I split the categories by priority (1: definitely; 2: I'd like to, but; 3: unlikely). At the end, I voted in 8/8 priority one, 5 / 7 priority two, and 2 / 5 priority three.
Categories voted (with links to the details): best novel, novella, novelette, short story, graphic story / comic, series, fancast, professional artist, fan artist, fan writer , fanzine, game / interactive work, and dramatic presentation - long. Plus the two Not A Hugo categories, astounding new writer and lodestar (YA)
Originally I wasn't going to vote in either of the dramatic presentation categories, because of the difficulty in accessing the materials. I sourced opinions from the Offspring, which worked for long form, but there wasn't anything from them on short form. I also wasn't intending to vote for either of the editor categories, because they make no sense to me. I'm sure that for others, these categories are incredibly valued, but eh.
I had hoped to vote for related work and semiprozine; more so the former because I often have quite strong opinions on the nominees (although sometimes that opinion is 'NO'). On this occasion, I just didn't have the bandwidth to engage and finish some of the other categories.