Actually, as an opening DJ you almost want to set the mood deep and dark to start off the night. Normally in the US, the structure of a "typical" club night is opener [10-12 approximately], followed by the peak hour headlining DJ [12-2am] (in most US clubs). Some clubs are allowed to stay open later for afterhours, and will then have additional DJs later into the wee hours of the morning playing more underground styles of dance music. Clubs geared specifically toward afterhours follow the same general format but with different time periods - opener [12-2], headliner [2-4 or 3-5], closing [4-?]. As the opener you don't want to focus on whether your music is deep/dark, but rather the energy of your set. You want to SLOWLY build the energy throughout the course of your set and entice people onto the dance floor and get those bodies moving. Need to allow people to show up, take stock of the venue/vibe, and buy their drinks to make the club money. Opening is almost harder than headlining, because you really need to understand the mood of the crowd and curate a set that gets people moving but doesn't steal the headliner's thunder. Being the headliner is easier, in my opinion, because people showed up to hear your music and you can pump out slammers and really get the club rocking. You really don't want to go too uplifting in an opening set, until the last segment where you ramp up the energy and get your crowd excited to hear the headliner. With house, you're generally going to be playing either deep or tech house in most scenarios. Maybe throw in some true progressive house as well, not Swedish House Mafia "type" tracks. With techno, there's such a huge variety of styles, and you need to tailor your set according to whoever's headlining. All that being said, there's plenty you can do to "warm up" your set. With house, throw in some jazz/feel-good tracks in the 120-126 bpm range to get people smiling and remember they came out to have a good time. With techno, try to find some melodic techno in the minor keys to break up the "broody" feel of that genre. Ultimately, sounds like you need to do some digging and find tracks that accomplish the above goals and develop your library more. Hope this helps!