If you have a well designed/optimized website and a good product then the most important digital marketing practice you need to worry about is paying for online advertising. Specifically, I'm talking about search engine marketing and social media advertising..
Everything we accomplish in life is a trade-off between time and money. After 15 years in online marketing I've found you'll get far more efficient results by paying for some online advertising than spending countless hours trying to create marketing materials and hoping they'll be virally shared. Continually creating content is time consuming whereas paying for monthly advertising is quick and can get you to instantly appear at the top of search engines and place your organization in front of people most likely to be your customers. You can usually make/get more money but you can never get back more time. If you have the resources to create a lot of great content you should still be supporting that with paid online advertising.
I find it surprising that I've come to this conclusion since I've always been a proponent of content marketing and I still am, to a degree. I've put in a lot of time doing presentations, providing training seminars, writing articles, doing media interviews, co-founding a marketing association, hosting conferences, and attending networking events. Its frankly been exhausting. If you're up for this approach then power to you - It works long term but takes a lot of effort and time and luck.
I did all this content marketing because I had no money for advertising and now I wonder how much further I could have gone if I had supported my efforts by incurring some debt to accomplish paid push. The most successful online marketing I've performed for clients has always involved paid advertising and I find myself turning down projects where clients simply want a content or social media strategy. Content and social media simply just won't work on their own. You need to pay for some gas if you want to haul ass.
Often the reason most marketing fails is because people give up on the effort or cost involved. It takes a lot of consistent work requiring energy, creativity, and follow-up on a daily basis. Marketing is the first thing that gets dropped when other priorities pop up, and other priorities will always pop up. So, if you're trying to come up with a bunch of marketing ideas like contests, events, flyers, trade-shows or partnerships then save yourself some frustration by simply launching some online advertising campaigns even if it's just to test some of the content ideas you have.
The sweet spot of advertising is when you stop interrupting what people are interested in and become what people are interested in. Just remember you're still going to need to pay for it - At the end of the day it's not who you know but who knows you.