You may already have an idea of how you can prove this to yourself, but there are some important details to consider. Obviously the first thing you need to do is to figure out how to do this. I'll explain that below.
One of the other things to consider is how memory of astral projection works. Astral projection occurs during sleep (remote viewing takes place in deep trance when you're awake, but I know less about this, so I'll just explain things related to projection). In order to remember what happens, you need to follow the same procedures as you would to remember your dreams.
>keep a dream journal
The more attention you give to your dreams, the more easily you will remember them. Writing down what happens during your dreams helps markedly.
>wake up directly after you dream
There are two parts to sleep: short wave sleep and rapid eye movement sleep. These occur in cycles of increasing length throughout the night (towards the end they take 90 minutes or so together). Without going into too much unnecessary detail, dreams occur during REM sleep. If you don't wake up directly after REM, you are far less likely to remember your dreams, because they will be in short term memory while you go through SWS and your brain processes other things. You'll have to figure it out more specifically for your own subjective conditions, but try setting an alarm for four and a half hours, six hours, seven and a half hours or nine hours after you go to sleep (with maybe fifteen to thirty minutes on top to account for the time it takes for you to get to sleep).
>don't smoke weed
Smoking weed inhibits the depth and length of REM sleep. You may have heard of or experienced the idea that people who smoke weed don't dream. The reason you want to remember your dreams is because astral projection occurs during sleep, so it's the same process.
Another thing to take into account is your ability to alter what you perceive during astral projection. I'll explain further how important this is when I talk about a different topic (about these things called thoughtforms), but all you need to know right now is that, when you're projecting, if you think of something, it'll happen. If you think of a place, you'll instantly be there. If you think of an object, you'll see it in front of you. If you think of a process, it'll happen. What this means is, when you use astral projection to find physical information you didn't already know, if you have even the slightest feeling that you can predict or already know what this information is, you'll see what you think it is rather than what it actually is. This includes subconscious feelings (maybe you've been conditioned to expect a certain thing). In order to gain the correct information, you have to be entirely curious. You can't have any expectations or you'll screw it up.
There are a couple other minor things to consider.
>I don't know much about Circadian rhythm, but I've heard it's important to go to sleep for the first time in the night before midnight based on chemicals in your brain like melatonin.
>you'll be using an alarm, so you might have a tricky situation to figure out if you have a wife or whatever. Sleeping on the couch or on the floor in another room can actually be beneficial, since sleeping where you regularly sleep can put your mind to sleep more easily, and, as I'll explain, you don't want that.
>depending on how easy you find it to project, you may have to develop stronger willpower (as in way, way, way stronger). You're going to be in uncomfortable positions without the ability to move, fighting against your own brain. People who will probably have trouble are, for example, people who are addicted to things like food, porn/masturbation or drugs.
>you might also want to get into a regular meditation routine, to learn to control your thoughts. This can be difficult to figure out but I can explain some things related to this as well if anyone wants.