One of the most efficient ways to support someone professionally is to give them a recommendation on LinkedIn. These recommendations are often well revered by hiring managers or potential clients.
TIP: Don’t be afraid to contact the requestor and ask for feedback on what you should highlight in your recommendation of that person. He knows his own brand better than anyone, so go right to the source!
Here's a quick little "template" you can use that makes for a LinkedIn recommendation that's specific, honest, succinct, and helpful for the person you're recommending.