One of the charms of film photography is focusing your efforts to capture a photo and trying your best not to make a mistake. I think it forces you to become better. Because not having that immediate feedback you get when you take a shot digitally lets you stay in the moment and also gives you an urgent sense of "don't mess this up". It's frustrating in the beginning, but as you get more comfortable with it you get an idea of whether or not your shots are going to come out alright.
However, there's a lot you can never plan for. Notably, the dreaded light leak. This happens when the lens and camera seals aren't properly aligned, when you're changing a lens super quick and don't wait for the 'click' before you start snapping. Basically light is allowed to come in the lens and distorts because of the angle of entry. Pretty much most of the time, you can't control it
It can be a cool effect but, as is the downside of film, you only find out about a leak when you get your shots developed and thats never any fun. Over the couple thousand shots I've taken I've had my fair share of photos ruined. However, every now and again..some of them turn out alright..
I did however read about this cool technique called "freelensing" where by you take a lens and don't connect it but hover it in front of the sensor at a specific length to achieve a kind of tilt-shift lens effect. This guy Randy Edwards does it super well. He's just an all round awesome photographer but being creative with those light leaks is mind blowing.