Personally what helped me out is the Criteria Clarification Collection when I first started in case you havent checked that out yet. There was also this post that I found was very helpful early on too: top mistakes made when nominating and how to avoid them
Hope you find some of this information useful and best of luck on you future nominations! Always feel free to post potential nominations or nominations that are struggling to get approved in Nomination Support. Plenty of people here love to offer advice and have a keen eye on how to improve eligible nominations.