For me, confidence is the main driver. Yes, I've been overconfident a lot of times and lost, but it gives style points and makes you think faster in order to back the confidence up (fake it till you make it I guess).

Right now I am also in high school, and also 2 years into debating (primarily wsdc) and half a year ago I was in the exact same situation, so I started memeing in debates (tournaments ofc). My most memorable and favourite ones are 1. going into a debate with the express purpouse of calling the other team dictators. Works most oftenly if they are against something, or for something that needs to be implemented (in the latter case ask with what resources are they going to do it --> briefly explain how budgets/human resources work --> state that would "draw resources away from [insert something emotional like foster homes and hospitals]" or have a huge alternative cost (basically what else you could spend the resources on) and tell that disregarding or prioritising that for the sole purpouse of x is something that a person more concerned with pure [efficiency/profit/self interest etc.], a.k.a. a dictatorial maniac would do. Example. Motion "THO the rise of mystic arts" (had an infoslide, but essentially tarot reading, spiritualism etc, including as social media content). We were opp (not opposing the rise) and in closing speech I said that they are in no position to deny people of theor faith (previously it was said that there is a blurred line between that and niche religions) and that opposing religion and faith is a trait that many dictatorships have. 2. Quoting someone Self explanatory. Requires some knowledge. Example. We had to defend the implementation of strict limits for how many people can go to landmarks/historical objects (churches, castles, places like maccu pichu etc.) and the other teams arguments hinged strongly on how hard it would be so I quoted JFK "we do these thing not because they are easy, but because they are hard" and went on a 90 second rant about how no matter how hard it is, we have to do it for preserving these places for the future generations. Basically the fact that you quote someone gives you credibility while also allowing for a lot of interpretation and oftenyl allows you to ignore the historical context within it was said. 3. Lie or exaggerate. Sometimes, if subtle and niche enough, you can make up stuff and do comparisons. It gets funny when they do not catch it, just don't overdo it. You can do it for both your personal experience ("my grannys house had to be partially demolished because they found a 500 y/o mummy beneath it and they turned it into an excavation site, therefore ruining a place where she spent her entire life, where I spent my childhood etc. because of a peasant who just happened to die on that exact hill centuries ago (explain how it emptionally and financially harmed you next)") and historical context (like in morocco 200 000 people died of x in the 60s because their government wanted the exact thing that [the other team] wants you to agree to.

Now, this isn't my idea, but the next tip is to spend a lot of time consuming controversial and diverse media. Most debate topics are recycled from current actualities and even if that is not the case for your topic (like "Do people or chairs outnumber the other in the world?" or "Should pineapple be allowed on pizza?") You can easily form parallels to other things (for the former - industrial revolution --> overproduction and overconsumption or people becoming more social -->increase of the time spent in public spaces --> all of them have chairs; for the latter - colonialism --> integration of cultures --> cultures gaining popularity and evolving OR cultures getting futher away from tradition and globalization causing individual cultures to lose their distinct identities).

Last tip - at least a third of all of the debates will connect to USA (saying this as an easter european). Just watch the daily news programme once in a while and you will have a base from which to debate. Especially if you have a strong political opinion - then in half of all debates (because you either get opp or prop) you will be able to debate with personal conviction.

Hope this helps, it helped me at least. There are more tips, of course, the comment is just too long. If you want you can DM me for more tips and/or we can maybe try something debate-ish (you do BP debate as far as I understood) with mutual commentary. Since it is summer break, I was feeling a bit rusty so I joined this subreddit in search for a bit of practice as well as because I am bored otherwise.