There's a lot out there, but be prepared to open your wallet. The more in-depth courses I have taken, starting back in around 2014, have ranged from $1,500 to $4,000 (before travel, lodging, and lost revenue for your clinic) for two to five days of instruction. The classes have been great and I don't begrudge the instructors, the facility operators, the equipment providers, etc. their charges but they will put a dent in your finances. You may recover it later but it will take some time. The point of care ultrasound courses mentioned above are practical and not overwhelming and are probably the least expensive way to further your abilities. Short, weekend courses in ultrasound at WAVE (We Are Veterinary Education), Sonopath, and Sound can run around $1,800 or so on up to $12,000-ish for more involved training. I just checked the NAVC Institute page and their three-day course will set you back $5,500 but that includes hotel and meals (at least it did when I took a NAVC institute course back in 2014). Dental Courses at NAVC Institute are worthwhile as well, and I believe slightly cheaper. I felt I got a good grounding as a vet student but I took an interest in dentistry and picked up a few pearls at the institute. For those less lucky (and at least 75% of the participant there felt cheated out of "formal" vet school dental instruction--"lack of time" don't you know?), well, they were brought up to speed in four to five days. For orthopedic training, AO Foundation, the Oqendo Center (or Viticus Center, or Western Veterinary Conference, or whatever it is calling itself these days), and the Nexus Group are great. If you are interested in external fixation, IMEX Veterinary courses will get you off the ground pretty quickly. Various suppliers like Secures and Arthrex sponsor classes in various corners of the country fairly regularly. Ophthalmology classes (outside of those that re-cover basic examinations, tarsorhapphies, enculeations, and entropion reduction seem few and far between. Some years back I was lucky enough to stumble up a three-hour course at one of the mega-conventions which taught corneal flaps. I'd like to repeat something like that but have had no luck finding that sort of instruction. I check the offerings as the ACVO annual conventions but I've yet to find a class that fit my ability to attend. All of these courses have imparted a significant amount of practical training in short periods of time. The instructors have a "You can handle this" attitude (vs. the "here's what we can do at the specialist level but don't you even think about it" vet school philosophy). You will be told (rightly) that you just got your feet wet and you are by no means a diplomate (but we know that) and you will be encouraged to pursue more training, spend time with more experienced practitioners, etc. but you will also be surprised at what is within your grasp if you choose your cases wisely.
