We do carrots, potatoes, onions and brussels sprouts in place of cabbage. If SO asks, I do turnip too.
Don't add any salt to the liquid. The meat will be salty enough without your help.
Right after St. Patrick's Day, corned beef tends to go on sale. We buy a few extras and freeze them for later. We have them in a few months but not as part of a boiled dinner. We have it with any side dishes we feel like.
"If you want to make an apple pie from scratch, you must first create the universe." -Carl Sagan