Some martial artists operate on the premise that the more complicated and impressive a technique is the better it must be. Is this premise correct? To defend yourself, do you really need a vast arsenal, or just need to be highly proficient with a few weapons? How many techniques do you actually use in free-sparring competition? In no-holds-barred type competitions where almost any technique may be used, how many techniques are actually used?
When teaching self-defense techniques, many instructors teach numerous techniques from their art or from other arts. Many of these techniques are only useful in specific types of situation. Every time these instructors see a new "cool" technique, they teach it to their students or at some seminar or clinic. However, when training their students for competition, these same instructors concentrate on teaching their students to perfect a few, basic, highly effective techniques. So, from this, may we draw the conclusion that for life or death self-defense situations we should strive to be familiar with a vast collection of techniques, any one of which may get us killed; while for competition we should strive to perfect a few effective techniques that will help us win.
One of Bruce Lee's often quoted sayings is "Absorb what is useful, reject what is useless, and add what is specifically your own." I also advocate absorbing what is useful; that which is useful in most situations that are likely to occur, not what is useful in a specific situation that may never occur. Most people will live their entire lives and never have to defend themselves in any type of situation. If a self-defense situation does by chance occur, it will probably be the last time it or any other occurs. So, does it make sense for students to spend their training time learning techniques that are only good for specific situations that may never occur, or should they be perfecting a few techniques that may be adapted for use in many different situations that may occur. Unless you have a desire or particular need to learn as many techniques as you may find, then you should reject techniques that, although not useless, are not useful for you in your life. There is nothing wrong with trying a new technique. It may prove to be useful, or it may be useless as is but you may be able to add something to it to make useful for you.
Instead of seeking to learn as many techniques as you can, a better way to approach learning is to seek to learn all you can about a few techniques that work best for you from as many different instructors as possible. Many instructors may tell you the same thing, which reinforces what you already know, but sometimes one or more may tell you something you do not know that will help you perform a technique more effectively or efficiently.
Absorbing what is useful and rejecting what is useless is a noble goal, but it is similar to the goal of only absorbing the truth and rejecting lies. The problem with both goals is: how do you determine what is useful or useless, or what is true or a lie? Is a technique useless or a fighting theory false because it does not fit into your style? Or, is a technique useful to you just because it is used by your style. Sometimes it is difficult to sort the wheat from the chaff.
Watch open tournaments where different styles fight each other under the same rules. You will see many types of uniforms, many types of rituals, and many types of techniques and movements used in patterns. Some styles will seem polar opposites to each other, however, then they spar, no matter the style of the fighters, they will all spar with basically the same techniques. When sparring a person of the same style, fighters tend to fight the person in the way their style dictates (with many useless techniques). However, when facing a fighter of another style, they fight with techniques that have been proven useful in all situations and against all types of fighters.
By the way, we do not know if Bruce Lee practiced what he preached since he never fought in competitions. We only saw him in staged demonstrations, choreographed movie scenes, or sparring less talented students, where he also used many useless techniques.