How can i learn to speak slower?

Okay so i have much of my life spoken very quickly while growing up. The past few months (im 16 by the way), i have been trying to be more conscious of it. Many times my mom would say i need to articulate my words better. Well, now im trying to and it doesnt seem natural? or i seem to get tongue tied? i ume some of it is natural because the movements may be new to my mouth but im just seeing if its natural and if its just the learning process. thanks in advance