1) Website- I see a lot of developers that have a single blog page for all their apps. Look at the format of google play and match your website as close as you can to what google play has. Why? Customers are use to a certain format and like things that look familiar . Think like a customer when building a website and put the same effort as you were in programming your apps.
2)Social Networking-Make a twitter and facebook account. Any app release you have or updates post them.You can even interact with customers and get feedback directly from them. Use this as a tool to learn from real people and adjust your game or app based on feedback.
3)Make Niche Apps- There is no way indie developers can match the power of big companies. Rather than try to take on gameloft or EA focus on niche apps. Small apps like car locators or how to cook books. Small apps like these have been know to get more downloads vs making a game going against a bigger company. Small focused apps or simple games with great graphics can draw people to your app.
4)Post in Forums- Post your game or app in several forums. Be careful as many forums are not really indie friendly. Most forums have a section where you can post games or apps away from where regular forum users cant see. Also you might run into jealous developers who have nothing better to do then degrade your game. Post in several forums to bring in users but remember this is only a small part of your marketing efforts. This forums is very developer friendly though.
5)Rate Me Button- In your apps your should have a rate me button and a googleplay button that points to only your apps in google play. You can also have a button to your website to give the customer a more personal touch.
6) Paid vs. Free- I would suggest you make 4 to 5 free apps before making a paid app. Most customers do not want to pay and only enjoy free apps.