Technique 1
Performing the Rat seal, I gather my chakra from my circulatory system and send it into the earth, imbuing it with the qualities of rigidity and denseness. Using this chakra, I then cause the earth underground to shift, sending a large amount of earth underneath the opponent. Then, I use shape manipulation to split the large concentration of earth into 2 pieces and force them through the surface of the ground, both masses of earth appearing as two large sections of rock on both sides of his opponent [in front and behind]. The rock sections then close in on the opponent, crushing him inbetween the confines of the earth.
This is a nice technique, good for getting the jump on the opponent. It's quick, so it won't leave much time for your opponent to react if he has a chance to. If you can use this at the right moment e.g. if the opponent was using a fire technique like, say, Grand Fireball technique, summoning the earth sections in front of the opponent will cause the technique to backfire. In that instance, the fireball would explode and cause burns and concussive damage at the very least. Which brings me to another point. Despite it's ability to catch opponent's off-guard via the speed of the technique, it isn't very powerful. Granted, it would kill the opponent if left undefended, but if they use Chidori Nagashi or a sufficiently powered technique, they'll be safe from immediate danger.
Technique 2
Gathering a moderate amount of chakra, I send it into the ground beneath me. Then, I begin using that chakra to grind the earth into a fine sand. Tunnelling into the ground, I continue using the chakra to turn the earth in front of me into sand. Aware of my enemy's position, I begin digging through the ground towards him, moving rapidly. I then move a few metres behind the opponent, digging myself out of the ground without disturbing it. I then take out a few kunai and throw them, one aimed at the back of his head, another aimed at the base of the neck and the last one aimed at the base of the back.
This technique is good for getting yourself out of tricky situations and allows you to get some breathing room. It serves as a way to tactically reposition yourself and set up for other strategies, such as distracting the opponent with larger techniques and then moving in for the kill yourself. This technique's main weakness is common sense. If the opponent is not above, in front of or behind you, it is likely that they are underground. With this in mind, the enemy can then cave the ground in on you or use any appropriate technique to kill you.
Technique 3
I draw chakra from my circulatory system and send it beneath the opponent, giving it dense and rigid qualities. Then, I split it into multiple portions. Forcing the chakra concentrations upwards, spikes of earth shoot up from beneath the opponent to skew them in places such as the arms, legs and stomach.
This technique is very similar in nature to the Bedrock Coffin technique, except this one is a little faster and arguably harder to counter. Also, this technique has the added advantage of being usable even on other earth techniques of your own. This allows for much diversity in it's uses, such as isolating the opponent on a panel or section of earth and then using this technique to deal a lethal blow.