+1 to what Mr. Cannon
But, if You're bent on DIY, perhaps a DIYholic like me, here's one way:
#1 Lay a painters tape across the belly so it's centered lenght-wise on the inner F-hole notches.
#2 Find the center line of the string path, and adjust/compensate a bit if the neck side measurement and the end pin measurement don't meet.
#3 Locate the center line of the bass-bar and transfer that location to the tape.
#4 Mark the treble side foot center onto the treble side of the tape, to the same distance from the CL as the bass side mark is.
#5 Draw two lines on both sides of both of the bridge feet centers ~1.5cm from the CL lines (3 cm wide feet).
#6 Lay a stiff cardboard (~20cm*25cm) onto the belly and transfer those bridge feet markings onto the shorter side of the cardboard.
#7 Cut the cardboard so it's a rectangle that has the same width as the outer edges of the bridge feet.
#8 Cut a generous relief between the inner leg markings.
#9 Trim the "legs" so they conform to the belly contour when upright.
#10 Tape the template upright to the middle of the tape.
#11 Decide the string height at the end of the fingerboard, and tape something there that equals that height.
#12 Using a long straight edge, transfrer the FB profile onto the bridge template.
#13 Unless You're preparing to install adjusters (and even if you do), add 2 cm to that height.
Now You have the dimensions that define the rough geometry of the bridge, the rest of the design is up to you.
You can copy some of the classics, or come up with something unique.
Instructions for mating the feet onto the top can be found on other threads in TB.
Plenty of them elsewhere over the 'net as well, but over here at TB You can communicate with the people giving those instructions (and defending their
way) IMO better than on some other sites
Good luck, and please don't hesitate to post at least the result(s), we all start from somewhere.