Untouched by the splendour of the ornaments, a stone Buddha sits in Bangkok, Thailand.

Usually, I’m very reluctant to use filters: polarization filters are very nice to eliminate or enhance reflections, make for a much more dramatic sky or saturated colours.
I sometimes use a neutral gray filter to reduce contrasts (the filter darkens the bright parts of the picture) and a UV filter may be handy in the mountains or at the seaside.
Colour Filters are something different altogether: even if you can change the colour of the sky to a beautiful blue, the rest of the photo will make clear that something is wrong.

Here’s one example, where I liked the effect of a tobacco filter:

Without Filter:

In this case, I prefer the mood with filter to the unfiltered original. It actually comes closer to what I saw on this rainy day in Blandy’s Garden, Madeira (Portugal)

Some photo tips.