Hi Lock, "Try out" has an experimental flavour as compared to "try". We "try out" something when we are unsure of the outcome before doing it. On the other hand, we "try" when we are simply trying to accomplish something with a more certain outcome. So, if you decide to use "try it OUT with my friends..." and "try it OUT on my friends...", it means you are inexperienced or experimenting in whatever you intend to do. Fortunately, in both cases, the result turned out to be great. Next point: "Try (something) ON (someone)" vs "Try (something) WITH (someone)": When we use "with", someone else participates in what we are doing; when we use "on", someone else is more of a receiver of our actions (or has little or no say in what's happening to them). For example, I would really keep my fingers crossed if my friend were to "try something OUT ON me" as some kind of test subject. On a separate note, it sounds unnatural to say "my many friends". You can say "many of my friends" or simply "many friends" instead. I hope this helps.

To me, whether to use 'with' or 'on' depends on what the method involves doing. Is it something you do with them? -> use with. Is it something you do to them? -> use on. Please note that 'my many friends' is not particularly natural English. Try 'many of my friends'.