Pulling and Attacking
If you're not already familiar with how to pull guard, please take a few minutes to understand the concept, then come back here. Now, sitting down immediately has its advantages, but virtually everyone can agree that if you sit and attack immediately, you're going to augment these advantages and take away some of the negatives. Here, we'll cover some different options from the guard pull: one sweep, one submission, and even one takedown. While pulling guard is often viewed as passively avoiding the takedown, here we're going to consider it taking the fight into offensive territory with no further delays.
Guard Pull Armbar
The guard pull to armbar combination is a great place to start with attacking, particularly if your partner already understands how you might pull guard. Recall that you are always trying to put your foot onto their hip on the sleeve side. Well, here, we're banking on your partner understanding that and placing the foot on the opposite side. From here, you can use the lapel grip to spin yourself perpendicular, and then lift your hips up off the ground to close the space in between you and your partner. You are armbarring the sleeve-side arm, but coming up with the other foot, initially, so this technique can be difficult to see coming.
Similarly, this next technique relies on your partner's reaction to some extent. Start by lifting your left leg ("sleeve side" leg this time) as though you are going to plant your foot on your partner's hip and sit down, possibly elevating them overhead (we'll get to this). Your partner is likely to sit their weight down and back to their heels in order to prevent being dragged completely into your guard. Now just put your left foot on the ground instead of stepping on their hip. Keep your lapel grip with your right hand, but release the sleeve so that you can reach across and grab their left ankle with your left hand. Just pull the ankle forward as you push their chest (via the lapel grip) back, and you can finish an ankle pick takedown. Passing the guard on the way in is a high percentage add-on at the end, too.
This last technique is a great addition to the guard-pulling family of techniques. Start by gripping their sleeve with your left hand, and their collar with your right hand, just like before. Step onto their hip with your left leg. Now this time, instead of sitting at an angle and trying to close your guard, try to scoot further underneath their hips (and hence their center of gravity) with your supporting (right) foot, which is still on the ground. Once you are completely underneath your partner here, it's a simple matter of pulling their weight forward and up with your lapel and sleeve grips. You can also use your second (right) foot in their hip to help facilitate lifting your partner up and over your head. Be careful if you're dumping them onto the ground, as neck and shoulder injuries can be common with this type of sweep or throw.
Attacking and Defending
Borrowing liberally from judo, these three techniques all combine a sacrifice concept with a direct attack. The armbar isn't a flying armbar, but a sitting one; you get to attack for a submission and perhaps have a chance to end the match right then and there. The ankle pick is a guard pull fake that relies on your partner understanding that you might sit to guard, which they really might not want for a variety of reasons, not the least of which is that they don't typically score points in a sport jiu jitsu contest if you pull guard first. Finally, the overhead sweep catches your partner cleanly off guard when you sit to guard, but then amplifies the effect by leveraging them up and over your head. All three of these result in immediate scores or victories, and all are accomplished once you understand the more fundamental guard pull concept. As always, keep me posted as to whether these work for you!