A better link is
Setting the clamping of direct samples is the most important one, but it helps to also set the indirect.
Other than that you’ll need to let the scene converge with a larger sample count, especially when you use glass-type materials.
Edit: turning down reflectivity of some of your materials may help too - it looks you have lots of highly polished surfaces. Personally I find that a bit too artificial. Lessening the reflectivity also lessens the speckly effect that ‘low’ sample count can cause.
p.s. I added the Raytraced tag to your post.