Chosen a location? Don’t just assume it will be OK. Visit it before the shoot. Check that you can get permission to film there, if you need it. Check the light. Check that there won’t be any interruptions or distracting sounds. Check there’s space to get all the camera positions you need.
Make sure you get any legal agreements – e.g. actor release forms – signed before you start shooting: you don’t want to be arguing about these after you’ve completed your film.
Make sure you’re confident with your equipment before you start filming: spend time practising on short films that don’t matter before you start serious filmmaking.
You should shoot a bit more than you need, but if you shoot hours of footage it’ll take you forever to sort through it to find the bits you want. For a one-minute drama film you might need to shoot between three and five minutes of video. Documentaries – where you can’t control what there is to film – will need much more than this.
Watch what you’ve filmed and check it’s OK before you leave the location. Is the colour right? Is the framing right? Have you got all the shots you need?
If you’re recording live sound, pay particular attention to the sound quality and make sure to record some background sound or ‘ambience’ which will help with the editing.