The sign-off on any emails you send shouldn't be wordy or high maintenance. There are various phrases that are professional and kind enough for the closing of an email. Some examples of effective signature sign-offs are Best, Warmest Regards, and Thank You. Each of these is professional, to the point, but still kind. Different emails may call for a different energy in the sign-off, but always remember to include one as a way of ending your message.
When you're writing professional emails to colleagues, you want to make sure you include your contact information. This gives the receiver of your email all the information they need to get back to you if they need it. Keep it simple and concise: add your name, your position and a relevant link or phone number. This is not the place to promote your projects or add a ton of detail. Keep it clean.
A simple thank you is also a solid option when you want to express gratitude. But, like thank you in advance, it can convey a tone of expectation. Save it for when you really want to imply, "I hope you do this."
Are you writing a cover letter? Sincerely convey the right tone for formal correspondence. Be aware that you are likely to appear congested in more casual business emails.