just follow a bunch of people you are interested in. There are some people who simply follow everybody that follows them and have thousands of followers but very little influence. On the other hand I spent 2 years building my Twitter account and can tweet out a link for lots of traffic from interested people.
Follow same interested people and they will follow you, no certain time fixed for tweet, but do not do any activity that shows spam so your account may disable
Follow people, remove those who don't follow back, rinse and repeat also don't spam twitter, post interesting stuff and ppl will follow
Decide your 'online avatar' just like a blog do not just spam out anything. Create interesting tweets that provide value or information. Be creative. Make sure that you only have a link in your posts every 3rd tweet. @reply to people with similar interests or with content that interests you. Treat twitter like a party, who do you want to talk to , what do you want to talk about, how social do you want to be? Ask questions that relate to you and the people you follow.
To Populate a Twitter account there are different ways to populate an account Read the article from there (eTechDNA) and i hope you can get your desired answer.
I generally go to twellow.com and add keywords to the search bar. You don't even need to log-in at twellow for this to work. Have had greatest success by searching via Twitter Profiles. Like "photography", "cooking", "gardening". Like wine and marketing guru Gary Vanerchuk says: "If your niche is 'Smurfs', then Smurf it up, baby!" Can't go wrong with that advice, no matter your chosen niche.