I I remember the early days of DVS when Serato SL1 first came out. It seemed like the perfect marriage of vinyl and vinyl emulation. After years of playing vinyl and then switching to Serato, I sold off my Serato SL1 boxes. I felt that it was making me lazy with mixing and technique. I eventually got another SL1 box recently so here is my advice to digital DJ's that have never DJ'd with vinyl (in no particular order).
#1 Know thy track: You have to know the songs you are playing inside and out. Dissecting music is essential
#2 Don't DJ with tracks that are of inferior quality. Strive to keep your collection at the highest possible file format setting. 320 for MP3's 9/10 for OGG's, or just use WAV and AIFF files. Portable hard drives are cheap right now.
#3 Get your face out of the screen. If you know you're tracks and have prepared your play-lists your chances of interacting with the crowd and being aware of your surroundings will help you create a better vibe. The crowd wants your attention...it doesn't want you to be hidden behind a screen.
#4 Learn to beat match...it doesn't hurt to learn. However, if you just don't want to learn, incorporate the dynamics of a track to make your transitions work better. Learn your tracks and you'll see that some songs beg to be mixed in and out of.
#5 Don't mix out of a song during the hype part of the song. This pertains more to hip-hop DJ's. I can tell when a n00b is DJing because they cut the verses off or the chorus off when the crowd is vibin with that part of the song. AGAIN: Know Thy track.
#6 Develop your own style. This one is tough. I developed my style from listening to elements of other DJ's I like and then incorporated my favorite things about beat juggling and skratching. I guess you'll have to hear me mix in order for me to explain...but...style also comes from learning the gear. I once saw a HOUSE music DJ do a mind blowing set with the old Pioneer CD100s and just a few CD's. He used the effects tastefully to add dimension to his tracks during some of the breakdowns.
#7 Practice Practice Practice - I know DJ's who used to practice 5 to 6 hours a day. Ridiculous right? Well I don't have that kind of time but when I do have time I sometimes do mix sessions for 2 or 4 or 6 hours. And sometimes I just practice my cuts for about an hour or two.
#8 Session with other DJ's of whatever skill level. You'll find you'll learn when you teach and you'll learn when you're taught something new.
#9 Make backups of your drives and have extra of EVERYTHING. When you go digital, things go wrong. Have spares of things like headphones, headphone adapters, cables of all types. Vinyl only DJ's have extra slipmats, needles, carts, head-shells, 45 adapters. etc. Keep a bag handy of all your emergency needs. Even keep an extra bag in the car with your spare and extra DJ goodies.
#10 Have fun. Enjoy the music you play. Don't spin music you don't like if you don't have to. Don't try to please everyone. You'll only frustrate yourself, promoters, and the crowd if you try to please everyone 100% of the time. Remember you're doing this because it's FUN and a GOOD TIME.