I am playing a three show gig this weekend. I am running a Les Paul through an orange combo. I am running it through a route 66 compression/overdrive, danelectro delay, line 6 green loop station pedal, and a full-tone overdrive. It is a smaller venue (800-1000 square feet) and I am wanting to push my tubes but maintain a low volume. Any tips?

You didn't mention which 'Combo' you have, but the easiest way to get about a 30-40% reduction is to remove 2 of the output tubes (a complementary pair, and assuming it's got 4 output tubes), then setting the output transformer's speaker ohm selector switch (if it has one) to 1/2 the rated speaker impedance: IOW, switch at 4 ohms to drive an 8 ohm speaker. If it has no switch, add a speaker in series with the existing speaker to bring the ratio up from 1:1 to 1:2.

Make sure you know how to ID the correct tubes as complementary before you try this. It's basically how Mesa used to do it, but with switching instead of tube pulling.

Best, Paul

A note about pulling tubes:

This is a practical way of reducing power and is used by some players. However, your output transformer plays a role in the nature of your distortion tone, many claim that while the tubes are being pushed, the transformer will not saturate and therefore someof the valuable nuances of your cranked tone are lost... This is why some amps use actual power reduction circuits rather than tube eliminating cicuits. Further more, sound power is based on a logarithimc scale (db) thus a 100 W amp is not twice as loud as a 50 W amp, rather the the diff is 3 db.
of courese 3 db is enough to drown the other guitarist out but whether it is all that much easier on the human ear in a small venue is debatable.

If you do not have a quartet powered amp then pulling tubes is not an option and u must use a power attenuator i prefer thd to the marshall power brake.

IMHO the best way to reduce the volume of amps is to use a speaker simulator, which allows u to send your cranked signal in to a pa without sending it through your cab/speaker. Technically u could crank all the way and ease your pa volume up to a whisper. However, my pa head is an all valve fender...I wouldnt dare run my amp into some solid state power amp..u might like it however, and it is definitly nor bad...
do check out the new marshall 5 watt amp that just came out! I love it so much (i have only heard in on demos) im just itchin to get it. I think it will be the best solution for folks like me who love brit tone but dont need the huge volume.