Ishant has everything a fast bowler needs. If he concentrates on the two most important things, he should serve India like Zaheer Khan for the next 10 years or so.
1 — His fitness and injuries. Know your body and listen to it, keeps things simple)
2 — Be consistent, play to your strengths and focus on mastering them.
The following is a technique used by a one-time fast bowling hopeful, who was victim of family pressure to concentrate on academics, and also to a larger extent, of a prejudiced cricketing system where regionalism, money, politics and nepotism play big roles.
This technique is recommended by my coach and colleagues (including pace guru TA Sekhar) and even legends like Curtly Ambrose and Wasim Akram:
1 — Use one stump or an iron rod or rebar, at least six inches shorter than the normal stump. Draw a batting crease, then draw thick lines every 18 inches in different colours up to seven yards from the crease. Then, put a bottle cap or one-rupee coin in the gaps between these lines.
2 — Start bowling with a tennis ball or taped plastic ball, focusing on the spot to be bowled at, and on hitting the stumps for at least 10 overs.
3 — Repeat Step 2 with a cricket ball for at least 150-300 balls. Use a variety of grips, wrist positions, and shine.
4 — Mark down the results.
5 — Monitor the results and make it a habit.
I hope this will help any aspiring fast bowler. I will be happy if this helps even one person.