Darren Rouse compiled a list of things to do to promote yourself without sounding like a jerk. Check it out here: https://problogger.com/tips-for-promoting-yourself/
You may have seen some of these individually in other posts. One of the UseMuse favorites is #4 - be learner. You will benefit in two ways - one just by learning about a subject and second by sharing what you learned you are helping others.
You can share straight up what you learned and also what worked to didn't work for you. This helps build your knowledge, credibility and good karma.
There is no down side here - keep learning! (and sharing)