You could use "presented to [friend's name] by [me]." It sounds impersonal, without feeling.
If you want something more personal, here are some options. It depends on the occasion, and how much space you have on the souvenir.
- With my deepest gratitude for all you've done, [your name]
- Thank you for everything, [your name]
You could search for greeting cards on the internet and that will provide you with many options.