Quick punches are a good thing at any time. When in doubt, hit. Snappy punches to the solar plexus (down and in), jaw, nose, bicep, kidney, liver are good. Downward chopping motions with hammer fist work well on nose, forehead, collar bone, solar plexus. Upward bolo with forearm to groin or arm is good. Sideward bolo to head is good. Bolo strike uses bony portion of forearm behind wrist.
Kicks: you don’t have to, and probably shouldn’t, kick higher than waist level, as anything higher should be taken care of by the hands. Stomp the instep. Use the inside edge of your shoe to kick the shin or knee with a ‘purring kick’. Thai style shin kick (using your shin as the striking surface) is good against the side of the shin, knee or thigh. A shin shot is more likely to cause the opponent to fall, a knee shot can severely damage the knee, and repeated hip shots can cause great cramping and dysfunction of the leg muscles. The old knee to the crotch is good, as well as a snappy front kick to same.
Never spend too much time going toe to toe. Hits should be thrown HARD and FAST while closing to initiate grappling. The objective should be control of his skull, using a neck crank, front face lock or other such neck manipulation. These are painful at a low level of force application, and lethal if more force is applied, snapping the neck. This can inspire great fear and respect from someone, having such control, and can diffuse a situation.
It's also good to get him down on the ground as fast as you can, and from there you can run away, or stomp his guts out. Judo throws are effective after lots and lots of practice and study; learn the three most popular judo throws: Seoi Nage, Osoto Gari, and Ogoshi. Also effective is to grab both of his clavicles with your fingertips and pull forward and down.
When you hit, hit as hard as you can, preferably to the head. The jawline just in front of the ear is considered the ‘button’ for a knockout, as the shockwave of being hit here goes straight to the brain stem. Knife-hand strikes to the back of the head can also cause unconsciousness for the same reason.
Don't block. Blocking is basically just waiting to get hit. Be proactive. Attack his hands, grab his wrists. Attack his targets. Overwhelm him with force and speed. Make it hard for him to attack you. Have an offensive defense.
The wing chun Bong Sau/tan sau principle is very useful, the idea of a protective bar in front of you. It is much more effective at deflecting attacks than the traditional cross body block, and it is able to counter attack at any moment.
Trapping should be intuitive. Use your hands, grab and push his arms to keep them from hurting you. control them. Position your arms for optimum power. Be fast and economic. Don't over extend. But as the experts say, don’t seek to trap in a fight, just let it compliment your boxing, and if you need it, use it, but don’t look for a chance to use it.
Footwork is constantly changing. Don't just imitate Bruce Lee, make sure you are able to advance, dissolve, shift direction, in any combination and all the time.
The original SPBK stance is observed.
Physical training was a big part of Bruce Lee's personal style but it did not carry over to the art as it is taught in modern JKD schools and I believe it should, as physical fitness was a big part of Lee's philosophy. He desired strength and speed, minimum body mass, maximum muscle density (high reps low weight after low reps high weight), and a high power to mass ratio. Many of the principles of JKD, like no telegraphing punches and kicks, require a lot of explosive power to work. For punches, train the abs, lower back, lats, chest, triceps, and deltoids. Lots of waist twists. For kicks, train the hip flexors, lower abs, lower back, quads, calves, hamstrings, iliotibial band, abductors, and buttocks. Train for flexibility, strength and stamina.
Observe animals. Watch the chimps at the zoo, the monkeys. Watch two house cats fight, how they use downward circular clawing motions, like those found in wing chun.
Study wrestling. Study greco roman wrestling and freestyle wrestling. Learn the old time illegal holds. (catch as catch can.)Compare these styles to Brazilian jiu jitsu and judo.
Study boxing, especially old time bareknuckle boxing. You will not be wearing gloves, so you must learn to hit with bare fists and learn to condition them. Make a fist by rolling your fingers up to your hand. Ladies, if you have long nails, you can fold your fingers flat against your palm. Strike with the knuckes of the last three fingers; pinkie, ring and middle. These knuckes line up in a straight line. Also, make sure the back of your wrist is in line with the back of your forearm. Do not curl it out or in. Looking at the inside of the fist, the bottom of the hand should be in line with the bottom edge of the forearm. Making sure of these things will ensure you doin't sprain your wrist when you punch. Both bareknuckle fighters in England and the states used the vertical fist and hit with the bottom three knuckles. This is the same as found in wing chun. Karate paractitioners use a horizontal fist and strike with the knuckle of the index finger, but this is for pressure point strikes. Those bones can break easily so I wouldn't recommend punching this way.
The palm strike/slap is largely underrated. More power can be generated with a slap than a punch. Use circular swings to the side of the head, aiming for an ear. Swing your whole trunk into the blow, arm fully extended for maximum velocity, and step with it. You see this a lot in Tai Chi.
Never hit someone in the mouth, mouths are full of sharp teeth.
The knee is a good target, especially against a larger adversary. Keep this in mind in your footwork that your knee is a target as well.
Study epee rules of fencing. The whole body is a legal target. Therefore the closest targets are the most popular; foot, knee, wrist. These are relevant targets in fighting.
Train your grip strength. Pull-ups, towel pull-ups, rope climbing, grip devices. Your life may depend on wrenching a knife or gun from someone’s hand, or a bomb switch. But most importantly, grip strength is essential in grappling, for controlling the opponent’s hands.
Pain compliance techniques and submissions can be good for competition, but unless backed up by lethal force, like the neck crank, or maiming force, like an armbar used to break the arm, they only offer temporary control of the situation. It is likely you will have to do some damage, and you must be psychologically prepared for this. If you wrestle submissions, you are used to being friendly with your sparring partner. It’s important to remember a fight is not sparring and an assailant is not your sparring partner. He’s the real thing. ‘Nuff said.