Even though seeking to completely control one's tells is a good goal to aim for, it may be a good idea not to give them a chance of happening.
One way of accomplishing this, noted in Phil Gordon's Little Green Book, is not to look at your cards until it is your turn to act (before the Flop in Texas Hold'em).
Or, to state it in a more general way:
The less we know, the less we can give away.
Of course, knowing less is often a disadvantage, so we'll have to weigh up carefully how much information we'll keep from ourselves in order to keep it from attentive opponents. However: Not looking at our hole cards before we have to means less time for our opponents to get a read on us, while we would probably not profit from knowing our cards at this stage. Furthermore, it prevents us from losing interest in a hand prematurely when we could be observing our opponents carefully, trying to put them on a possibly range of hands.
Another solid strategy (also taken from the Little Green Book) is not to vary the size of your bets according to the strength of your hand. This seems weird at first, but when combined with a tight-aggressive approach, this can go a long way in concealing your hand from your opponent. After all, the real reason we are trying to avoid tells is that we don't want our opponent to know, or have a good guess about, the actual cards we are holding - betting medium hands weakly and strong hands strongly while checking/calling when we have a draw will give our opponents a good idea about what cards we are holding.
Corollary: play less hands (tight), and do not vary your bet with the strength of your hand (i.e. bet the same amount with JJ, AK and maybe even occasionally T9 suited before the flop). However, once in every few hands, reverse your betting pattern by slowplaying a big or medium-strength hand, confusing those who are trying to analyze your play.
Every time we bet or raise, we are forcing our opponents to make decisions. The way they react to this forcing serves as an indicator of the strength of their hand and their willingness to play it - we are forcing them to give us information about their hand, while simultaneously representing a strong hand (whether we have one or not).
This answer contains just several small aspects of the big picture - a true answer to your question could fill books (and books have been filled with just that topic). However, I hope the above thoughts provide a starting point.