A nicely layered neck can be a stunning addition to most outfits. A mix of old and ne, expensive and more affordable pieces is great to make it personal, and to tell your story perhaps add in some family heirlooms.
Stacking multiple delicate chains can be a stunning look, but thinner chains can tend to tangle more. Thicker chains and different lengths makes this easier, and the varying sizes of chains and pendants means you can better see the individual pieces - and also prevents the chains to tangle as much as thinner chains. The Wilma or Frida is a great chunky piece to use for a heavier piece, then add the Felix, Amore or Colette for more delicate detail.
When it comes to stacking bracelets, I always find that building from a foundation of some solid bangles works well. Then I tend to add some colour, and and some structure in form of fabric or chain. Again its all about mixing fine with chunky and keeping it fun. Enjoy exploring and have fun!