I don't really have many tips for getting more followers. However, if you want your account to stay relevant, like GoronGainz said you need to post every day, or at least very frequently. Said posts should be interesting too, in order for people to remain interested in your content.
Using popular hashtags can certainly make people see your profile. From there it's just a matter of ensuring your content is interesting enough for people to want to follow you. Going along with this, I believe it goes without saying but don't keep your profile private unless you post personal information (which I don't recommend in any case) as people who don't know you won't be able to see any of your posts.