Something I've found helps me is to make a template, a piece of paper the length of the necklace or bracelet I plan to make. I can lay the clasp and pearls on it to check the spacing, and more accurately judge how long the pieces of chain need to be. A tape measure and some basic math, marking the paper at equal intervals will give you a permanent guide to easily repeat your design! Be sure to include the approx length of your wire wraps; otherwise your bracelet could easily end up anklet sized! Count your links in each section of chain so they are exactly the same, or hang them from a straight pin and snip evenly.
With a bracelet, you may want the pearls evenly spaced so the weight is balanced and the clasp doesn't roll to the top of the wrist. I'm sure we've all experienced bracelets like that. I check the bracelet length by turning the first loop on each side of the pearl and attach each link of chain without finishing the wire wrap until I have verified the bracelet is the required length. (I'll add a photo tomorrow.)
On a necklace, it is much easier, imo, to adjust a few links near the clasp if necessary to shorten the length. Also be aware that if you use a heavier pearl in the center, it will sag more in the middle instead of having the more rounded look; just depends on the look you are going for. If you want to use your tin cup with an enhancer, you may want an even number of pearls so a length of chain is centered instead of a pearl.
All chain, sterling and especially karat gold is expensive; you want as little waste as possible. Patterned chain, like figaro, will have more waste and is more challenging to get the pattern centered than rolo or curb, which have no pattern. Do save all scraps and recycle. Rio Grande has a good recycling program.
Excellent suggestions above for size of chain and choice of wire!
I am writing this after 9pm, and will check for errors in the morning, haha.
