At the end of the day, the burden is on the plaintiff or the claimant to prove that they were injured and they were injured as a result of the negligence of the property owner. Anything you can do to prove the evidence that the property owner was responsible is critical.
One of the key things that you can do is take photographs, take photographs of the area where you fell, the substance you fell in, perhaps what you were wearing, including your footwear. The more evidence you have of what caused the accident, the better. You should also take photographs of your injuries and document your injuries as well as going to the doctor on a regular basis, so there are medical records to support your claim.