I work on dozens of different marketing campaigns every week. Some seem really easy while other times we're trying to overcome ridiculous hurdles to do something that works. Every day I try to think about what and why worked in the past, and how I might be able to apply such for whatever I am working on. There are a ton of tactics, consumer trends and of course new technologies that can come into play, but come to think of it, if the three things below hold true then your marketing is going to be easy and successful.
1. You have a great product. Or at least a really good one. Don't advertise or market a product or service that you wouldn't want to use yourself.
2. You are customer focused. Answer your customers' questions. Participate in conversations about your product and category, listen and then act on the feedback you get.
3. You love what you do (and so do your employees). If you love what you do, then you're going to be enthusiastic about building a great product and telling people about it. Marketing will come easy because it will feel just like having a bunch of conversations about a topic you love.