In addition to getting Bronze at 300 tier points, you may be eligable for the bronze at 25 flights. If you travel to europe on "cheap" Economy tickets, you will only earn 10 tier points per flight.

When you reach 25 flights (so your 13th trip of the year), you will turn Bronze, and be eligable to use business class checkin, which can be a great help in some situations.

If you hit 50 flights (just over 2 returns a month) you get Silver.

If you fly long haul, you will be hitting 300tp before your 25th flight of the year, so that doesn't really count.

Make sure you have your BA number associated with all your bookings.

I'm not sure what a 75tp flight is. WTP used to get 75 tier points, but now gets 90 (100 if you're off to Singapore, Cape Town, Argentina or Tokyo) each way. This alone will get you Bronze after your 2nd flight.

I'd be careful about saying "very very frequently" on here. People on this forum have a skewed view of "normal" amounts of flying. I took my 59th flight of the year earlier this week, with another 11 booked and 8 with fairly concrete plans, but I just fit into the "moderate flyer" category, yet my friends, family and colleagues think I'm insane. There are some crazy people here that fly at least twice as much as I do. You can identify them because they have "BA GGL CCR" or "Travel Disruption Magnet" in their profiles