Depending on the conditions you hunted in, you have to be careful about leaving them loaded. If you were hunting in rain, snow, fog, or very humid conditions, pay special attention to your rifle. You might want to unload it and start fresh.
Try and maintain the same temperatures you hunted in, in the location you store the rifle for the night. I know some people take them in the house and claim they have no problems. I have done that twice and both times, had misfires the next morning. So if I hunted in 20ยบ temps, I store in that. I do not want to subject the rifle to any sudden temperature changes. What happens to glasses when you come into a house from being outside in the cold? They fog up. They develop condensation. Well your rifle barrel will do the same. I store my rifles after being out in the cold, in my unheated wood shop. They are out of sight, and mind then.
Next is, remove any source of ignition. Primers, #11 caps, musket caps, cartridges, pan primer powder, and batteries, all have to go. Remember, a flintlock can fire even without the pan primed. I like to put a clean dry white cotton sock with a little gun oil in it, over the frizzen. This will stop the flint from striking and sparking when the mysterious happens.
Also remove all muzzle mitts, finger cots, tape, condoms, balloons, what ever off the muzzle of the rifle. It will rust under those things and very fast I might add from experience. Then I take a oil cloth and wipe the rifle down very good to remove any moisture that might have accumulated on the outside of the rifle. I also then swab the inside of the barrel with dry patches to remove anything down there. Some people even put a light oil in the bore. I personally do not.
Next, I tie a red bandanna through the trigger guard of the rifle. This is a signal to anyone, friends, family, especially children that the rifle is loaded and must not be tampered with. Make sure they all know what the bandanna means. I had a nephew I really trusted. He knew what the bandanna meant. Yet like all young men loves to handle his uncles rifles. Well after dinner he was outside doing something. I walked outside for other reasons

and noticed him in the wood shop shouldering my loaded bandanna ties rifles. He did regret he was already in the wood shop. Believe me.
With the rifle treated, and everyone warned,I then place the rifle, muzzle end down on some cotton cloth in a corner. This is to allow any moisture that might form to run down hill, away from the powder charge. Also take some Q-tips and wipe the inside of the 209 area or around the breech and nipple of the rifles to make sure that is all nice and dry.
In the morning I use a dry patch and swab the barrel. And never use the same cap over the next day. That goes in the future range session caps.
Personally I have had misfires and it frustrated me. I am so careful, I follow all the rules of storage. But it is one of those things. The next day, when sitting on the stand, try not to think about the water that damaged the powder charge and the fact that when that monster buck does step out, the gun will not fire...