charging deep cycle marine batteries

[beer batter]

What are the proper steps to charging a battery each time?

Do you pull the caps to fill with distilled water each time? Do you charge with the caps off or on? Do you fill distilled water before and after charging or just one or the other?

I've seen people do a combination of all these. Just wondering if there is a single recommended way to do it to help my batteries last as long as possible.

[Surface Tension]

No need to check water level every time but it wouldn't hurt either. I check mine a few times throughout the summer. You don't need to leave the caps off when charging.
Put the clamps on then plug the charger in. When its charged unplug the charger first the take off the clamps.