| 1. Filters - Auto wahs, envelope filters, ans other dynamically controlled filter effects respond to your attach, you don't want to limit dynamics with compressors and/or distortion pedals that reduce dynamic range. Most players put wah pedals first in the signal chain-mostly to come before distortion effects. (notable exception - Tom Morello)
2. Compressors - Compressors can raise the noise level of everything that comes before them, so they should as close to the beginning of the chain as possible.
3. Distortion/Overdrive - Distortion and overdrive pedals prefer to see an unmodulated signal and the harmonics generated by a distortion device bring richness to any chorus, phasers, or flanging effects that follow.
4. Modulation - Tremolo, chorus, phaser and flanger pedals fit nicely here, due to the aforementioned interaction with distortion boxes.
5. Volume pedal - In this position, the volume pedal allows you to maintain a consistent signal from your guitar to your distortion devices, and get full shred at low volume. However you'll likely want to place delay and reverb effects after the volume pedal to ensure their tails continue to decay after the volume is cut.
7. Delay and reverb - These effects come last in the chain, usually delay then reverb, because placing them before distortion pedals can trigger a jump in the ambient effect level whenever extra gain is engaged. | 
