IMO.... the best place to catch crabs using a boat is by going through the Grand Bayou weir boat opening and do your crabing there in the marsh.
But..... this Marsh [East Cove unit of Sabine NR] is closed now so that is not an option.
South of Sulphur in the Sabine refuge, there are several good places to catch crabs from the bank. But on weekends, there will be lots of people. Since I usually only go to East cove to crab.... I don't know much about catching crabs on the west side. I have heard that going down to the West Cove boat launch dock is usually the best place to catch crabs in that area.
Go to the Sabine NR web site.... they have a good map showing the parking locations and all the regulations to follow.
This picture from a couple weeks ago, when Grand bayou weir access was open.