0% - D-throw > grab again works on some characters, and is a decent surprise move you can probably pull off once in a while. Don't get too obvious with it though. I think b-throw can chain together at 0% on some characters as well since it sends them really low and horizontal.
Low% - D-throw > u-tilt or u-smash is good. You can also use f-tilt, but it's a lot harder to follow up. You can also jab and use jab cancels to grab again. I believe f-throw > f-air works on bigger characters too and you can probably grab them after.
Mid% - F-throw or B-throw is a decent way to set up for a DAC. Look carefully at how they DI, or this could work against you. Though, at this point, grabbing is probably better to pressure them and keep thme away so you have space to use your projectiles more effectively. If you get them high in the air, chase them with whatever. You can time a hit as they land from an airdodge, or if they try to attack while landing, you can space yourself and punish them.
High% - At this point, you can probably just use throws to get them off of the stage and edgeguard them unless you've already done it earlier with a gimp. You can hit them upwards and read their airdodge with a good d-air to kill, or something.
Also, Link's u-throw kills most characters at like 160% from my experience. This is completely dependent on the opponent's character, DI, and the stage ceiling.
Other things you can do with a grab is retreat and pivot grab, which surprises people a lot. You can pivot grab to punish poor spacing like missed dash attacks and landing lag. It's also a really good trick to use on people to dash from in front of them to behind them and pivot grab. They'll normally try to spotdodge, or wait until you dash attack or something and they try to shield grab you, but you'll go past them and grab them. It's a cool trick to use on people, but don't use it too much. It adds to your pressuring options ^^
