I love embedding URLs (web links) into my email signatures. It not only makes them look professional, but it makes it easier for my mail recipients to use. Rather than hand-typing a web address or phone number, I simply embed the information so that all they have to do is click or tap on it. I also like for my email signature to be identical across all devices, so that regardless the device I send email from, there is a sense of consistency for my mail recipients (as much as I love my iPhone, I don't like the "Sent from my iPhone" generic signature).
iOS supports embedded URLs, but it's not obvious how to create them. In fact, there is no way to create them on your iOS device, so we enlist the help of Mac OS X. Here's how...
First, we want to open a new mail message on our Mac and create the perfect email signature. To embed URLs, simply highlight the word (or words) you want to create the link for, then go to Edit > Add Link...
This will open a new window prompting you for the URL you want to use when people click or tap on that link. In this example, I want to embed a link to my website. Continue doing this for the rest of your email signature.
When you're done, send yourself a test email to make sure all the links work the way you expect them to. If there's a problem, fix the problem until it's working exactly how you want it to (you can edit a link by going to Edit > Edit Link...).
When it's all done, and you have confirmed that it all works the way you want it to, send yourself one final email, but make sure to send it to an address that you can check on your iPhone or iPad. When you receive that email on your iPhone or iPad, simply highlight your new email signature (with the embedded links), and choose to Copy the text.
Next, we need to paste your new signature into the signature area of your iOS mail settings. Go to Settings > Mail, Contacts, Calendar then down to Signature. Tap inside the blank space and choose Paste. This will paste your signature (with links), and prep Mail to use this as your default signature.
Once that's done, it's always a good idea to send yourself one more email test.