My Maror has been weak the last few years. Any recommendations on having intense Maror?
Coarser = spicier.
Grind it as close to Seder as possible.
Store it in a airtight container (glass is better then plastic).
Freeze it until right before Seder.
ETA: If freezing it, there's really no need to grind it as close to Seder as possible. The freezing will lock in the freshness.