You can't do nothing with 30 minutes; You might as well just be an investor or maybe a swing trader.
To greatly succeed trading, you have to be able to allocate and watch the market from open to close.
Because you never know when the opportunity will strike or open or close. -- You have to be a calm sniper, or someone on a stakeout.
I am a trend-following trader, trading forex, indices, occasionally oil and gold, over multiple day time horizons. All my trades are opened and closed using pre-set orders off daily charts. I put in less than 30 minutes a day, plus about 2 hours at the weekend. I can assure you I am profitable.

