In addition to watching and playing the series in the even chances, another technique i use is when i see a trend of even chances developing in the most recent 4-6 spins, i will flat bet against that trend for it to continue for 1 bet, essentially hoping to break the trend.  It is betting for the 'Anti-trend.' 

Ex:  RR BB RR....take a chance here and bet R next.  Bet against this double pattern to continue.
Ex:  R B R B......take a chance here and bet B next.  Bet against another single.
Ex:  RR B RR .......take a chance here and bet R next.

Random shows both trends and non trends in the short term.  The flip side is when you observe a 'non-trend ' sequence, you can also take a chance and bet 1 unit for a trend to begin to form.  With practice, this can be a valuable tool to give you an edge flat betting the even chances.  don't bet every spin, and don't chase a loss.  If you lose your first bet, WAIT for another opportunity to bet against or for a forming trend.  Random constantly goes back and forth, it cannot stay on a trend for very long, it wants to change.  that's the true nature of random.  Think random, think chaos, and the game will start to play 'your game.'

Believe it or not, this alone can give you a significant edge flat betting.  Be patient, be selective in your bets, be surgical and bet when random is showing weakness, which is after a visible trend has formed.  Yes trends can go on for long periods of time, but those should be the times you avoid.  Look for other opportunities in O/E, H/L.

I just played 9 sessions flat betting and my results are as follows:

Session 1: +5, 49 bets, won 27, lost 22
Session 2: +5, 53 bets, won 29, lost 24
Session 3: +5 23 bets, won 14, lost 9
Session 4: +5 23 bets, won 14, lost 9
Session 5: +5 29 bets, won 17, lost 12
Session 6: +0 40 bets, won 20, lost 20
Session 7: +5 11 bets, won 8, lost 3
Session 8: +0 32 bets, won 16, lost 16
Session 9: +5 6 bets, won 6, lost 1

This is nothing but red/black, odd/even, high/low.  Only one bet per spin.  It's not a system, it is experience.  It is 'reading random' as Gizmo and Spike talk about.  I don't play trends and I don't bet every spin.  I look at the past 20 spins and make a decision based what is happening.  I do have a few rules I use to keep from going out of control. 
The most consecutive losses I endure is 2, 3 the most.  I can do this without writing anything down, just simply observing the history board, and reaching in. Many times the stream will be chaos, and I can avoid it, wait it out, or walk to the next table.  Its all about practice and really understanding what a typical random sequence looks like.  A typical random sequence has many very 'short runs' and just a few longer ones.  This is where I play.  I play inside a typical pure random stream.  Anything other than this such as tons of streaks, or tons of singles I avoid like the plague, it just doesn't work consistently for what I do.