Your lawyer is the best, and you want to express your gratitude. But what to say? And how to say it? Writing a thank you card is always a nice gesture and lets your attorney know you appreciate her work on your behalf
Be genuine. When thanking anyone, your best bet is to be genuine in your gratitude. Tell him what you think, how you feel and how you think of him. Let him know you'll be more than happy to refer other clients to him, or at least sing his praises to others when you talk about your case and how he helped you.
Write in long hand. Yes, it's old fashioned, and your handwriting may need some practice, but use a pen and write your note or letter instead of typing it on your computer. Using printed labels is fine, but a handwritten note is a nice touch.
Send copies to others. There is an old leadership maxim: "Praise in public, reprimand in private." This applies to thank you letters as well. Send a copy of your thank you letter to your lawyer's boss (if she has one). You can also write an op-ed for your local paper, file a positive report with the Better Business Bureau, and so on. It's up to you how much you want to praise your attorney, but letting other people know how pleased you are is always a good idea.
Follow up on holidays. If you send out Christmas or holiday cards, add him to your list. You never know when you'll need a lawyer again, and even if you never do, it's good to keep the relationship fresh in his memory.