It has been said that there will never be another Da Vinci; we've pushed the limits of human knowledge to such an extent that most new discoveries are made in highly specific areas in equally specific fields. True as this may be, we have also learned to limit ourselves by thinking it is better to be a master of one profession than a tinkerer in many.
Da Vinci may have been a genius, but the greatest fuel for his inventions and contributions to science was curiosity and a willingness to try. By opening yourself up to learning a radically different skill you'll find that you'll develop ways of thinking and problem solving approaches you may never otherwise have considered; it's time to multi-discipline yourself!
That thing you've always wanted to try: try it!
As we progress in our professional careers, we tend to specialize as a way to differentiate ourselves from our competition. The very nature of contemporary job titles says a great deal about our obsession with specialization - User Experience Designer, High-Fashion Photographer, Graphic-Novel Illustrator - and so on.
Think back if you can about what you wanted to be when you grew up as a child. I suspect you'll not find your 5-year-old self spouting off about how you wanted to pursue a career as a "Mobile Web Application Front-End Developer" (unless you were ahead of the curve - in which case - kudos!). Sure, it might be a little impractical to rewrite your resume to submit to NASA, and "Robocop" might not be a real job (yet...), but somewhere along the line you might have wanted to be a dancer, a singer, or a writer. There's no time like the present.
Be professional about it.
We all have hobbies; you may already play in a band for fun after work or take a pottery class. There is a culturally endemic fear of taking our hobbies to the next level. It is this fear which will prevent you from opening your horizons and realizing new potential. Think about your current career; at some point, you started learning skills which gave you a leg up over your competition and got you the position you have now. These skills were invariably the result of hard work and applying yourself to the best of your ability.
There's nothing wrong with doing something "just for fun"; if we didn't we'd collapse from the stress of exerting ourselves 24/7. But if you pick something to give more than a casual amount of time to, and to really invest yourself in, you'll quickly see one of the greatest virtues of being multidisciplinary: you'll become passionate about your new effort and make progress at an accelerated rate.
Being professional about something outside of your career can be difficult: you won't be earning a pay-cheque, you won't have your regular network to rely upon, and you won't have a set schedule to follow.
The trick? Change those things. If you want to get serious about your new passion, don’t be afraid to charge for your work. You’ll take more pride in it and, besides, it’s a bad practice to get in the habit of working for free. Just because you're a solo, aspiring guitarist doesn't mean you have to play the lonely blues - get out to open-mic nights, find local artists associations, and schmooze at industry events; you might be surprised at who you rub elbows with. You already calendar-ize your work, your gym routine, and your meals; make sure to budget an hour a day for your new passion for sculpture.
By the same token, avoid negative behaviours which would be considered unprofessional in a work environment. Don't miss your deadlines, anger your peers, or exaggerate your accomplishments; you'll torpedo your own success.
Bridge the gaps.
Da Vinci made amazing discoveries and is revered as a polymath because he took ideas from one field and applied them to another. If you start doing the same then you'll have some revelations of your own.
The first step to making these connections is simultaneous exposure. If you're an illustrator trying to take dancing more seriously then start sketching dancers. If you're a musician taking up welding then make sure to listen to songs you know and love while you put acetylene to copper. The idea behind this principle is that you can leverage the parts of your brain you have already developed and let them start working with the new stimulus.
It will be a gradual transition, but over time you'll start to think of the angles involved in your dance positions in terms of the familiarity you already have from drawing. You may find the sounds of putting a hot torch to metal inspire your next techno track.
Beyond this passive phase, start actively trying to connect the disciplines you're developing. At the end of the week make a quick table with two columns. Write the name of each field at the top of each column and jot ten things you've learned about each for the rows. Draw a line between concepts you relate - don't worry about what "makes sense" - the purpose of this exercise is for you to discover your own thought process. At the end of the month look back and review your weekly cross-associations; you'll start to notice patterns and over time these will become more concrete. You're well on your way to multidisciplinary problem solving.
The more the merrier.
The title of this article isn't "Bi-disciplinary You" for a reason: the more differing skills you develop, the more cross-associations and unique approaches to problem solving you can use in everyday life. The old adage "jack of all trades, master of none" has in modern times been used as a disparaging comment. Ignore that sentiment and enjoy the benefits of your new skills; you might just show the old-hats a thing or two.