You are doing everything perfectly correct. The voting power is based on how much HIVE power you have. So I have over 16,000 HIVE Power and my vote can go from about $.04 to over a dollar depending on the value of the HIVE coin that day. So you with 7 Hive Power, are likely giving a value right now (as hive is down in price currently) of around .0001 cent or so. When HIVE recovers that will improve, and as you build up more HIVE power that will improve. So just keep at it, keep voting on posts, leaving comments and everything you are doing and slowly over time you will build up HIVE power and your vote will become worth more.