So both my friends play marth and we're getting into competitive and I notice they wait for me to attack and grab me or they out-space me with their sword. Trying to avoid this I watched some videos and I notice people will nair SHFFL and go right into a grab/gentleman without getting punished. I try this but I still get punished even with L-cancelling. So i'm wondering how to improve that. Other things they do are spam dash attacks or run up to me and side-b and I can't get past the rang so I go up to avoid it but by the time I'm above them they're out of the side-b and can up-tilt me while i get stuck on the platform. I can't seem to find a way around this so any tips would be appreciated.