How traditional are you guys?
10th anniversary is aluminium/tin (traditional) or diamond jewellery (modern)
15th anniversary is crystal/ glass (traditional) or watches (modern)
Tin/aluminium -- windchime? sculpture or other art?
Diamond jewellery speaks for itself, really.
Crystal/glass -- paperweight? gorgeous champagne flutes?
Watches speak for themselves too.
Either way, hope you have fun. 10 (and 15!!) years is awesome. Congratulations.