These are a few of my personal favorite holiday gifts for coworkers:
Personalized Starbucks Cup - Coworkers and coffee go hand in hand. This Etsy find for only $10 with endless personalization options is perfect to fill with a gift card or chocolates.
Get Shit Done Planner - Will give your coworker a good laugh but also end up being super useful. Win-win!
Homesick Candle - If your coworker grew up out-of-state, this is at the top of the list for personalized and thoughtful gifts for me! Reviews speak for themselves, these are a hit with so many people!