How to get Band 1?

Hi, just asking for any advice on how to get band 1 on the day?

I've always gotten Band 1 on medify and Medentry, but I've heard these aren't fully accurate.

In official mock D I got around 54/69, and myucat says this is just a few marks off of a band 1, so how can I ensure I get a band 1 on the day?