1. Put on your favorite playlist, CD (yes some of us still use CDs), etc and when it gets to your favorite song, try to make it through the whole song without your mind wandering off. If towards the end of the song you realize you don't even really remember hearing the song, you're mind isn't focusing on the present moment. If you make it through one, try two in a row. See how far you can get. You may have to do this a few times to get an accurate sample.
2. Count how many times a day you begin an email, a document, a Facebook post, a text, a blog, etc and an hour later realize you never finished it because your mind went elsewhere. If you'd been focusing right on the moment, nothing (minus perhaps a true emergency that it would be dangerous to ignore, like your apartment catching on fire), you really weren't too focused on the moment while writing.
Ironically, as I type this I'm doing laundry and eating lunch. Case in point, right?
Personally, my mind tends to wander into the "daydream" realm, as well as the "pre-planning" realm. In daydream mode, I have ideas coming in from all directions and I'm extrapolating them out into actual potential activities. This is great for creativity, imagination, seeing your true potential, getting past a rut. Not so good for getting through the inbox. In the "pre-planning" realm, while I'm doing something else - usually something innocuous like showering - I'm writing emails and articles in my head, playing out a conference call I have later, etc. The issue isn't so much that I'm not paying attention to the shower itself (because really who cares), but that I'm feeding that constant monster who refuses to focus on the present moment. More or less, I'm not enjoying the present time because I'm focusing elsewhere.
So the other day, rather randomly as it often is, an idea came to me, probably in the shower. What if I created a catch word? So I did. Whenever I notice my mind going off into the wild blue yonder, I say this word - out loud if I'm alone at home, in my head if not - and bring myself back to the present moment. It sounds rather simple and silly, but it's actually working. It almost works like your kitchen timer would - "hey, foods burning over here, stop futzing around and start paying attention!". The more you use it, you'll probably notice the less you need to use it. Pick a word you wouldn't use much in every day conversation, but something basic enough that you'll remember it. I also suggest not choosing something associated with a hobby, a job, a pet, etc. It shouldn't really carry an alternative "meaning" to you.
A key to this, though, is to then set aside time that your mind can wander. You don't want to squelch your creativity, imagination, or dreams. You just don't need them to come in the middle of a board meeting. So set aside a few hours a week, or even a little time every day, to give your creative brain some "alone time."
Final tip - don't tell anyone your "secret word". Remember when we were little our parents created a secret word for us so that if someone came to pick us up after school (who wasn't them) they had to know the word or we didn't go with them? Maybe that was just us. Anyways, it's like that. It's for you, and you don't want anyone to use or abuse it. If you give it a try, let me know how it goes. I always love to hear what works for others. If you have another 'in the moment" trick, I'd love to hear that too!