map a lot. if you find a song and think "wow, this could be an osu! map", map it. no matter how many beatmaps you created in the end
also, it helped me to look at maps i like in the editor. i mainly looked how they mapped it so that i can bring it up in my maps too.
i remember the time i bothered mappers to look at my shitty maps to give me their opinion and criticsm so that i can improve better
dont give up on yourself, being good at mapping takes a lot of time