X Guard can be a fantastic position for sweeping an opponent with really good base. Any time that you can get your hips under your opponent your ability to challenge their base becomes increased.
There are literally countless ways to enter into X Guard. Over the next series of videos I use the same entry. This is a very easy entry and it focuses on good hip movement and body angle. Please do not think this is the only way to enter, nor do I think it is universally the best way to enter into X Guard. For me it works and for a lot of my students it works.
Make sure that you start off with both feet on the hips and push your partner away. I refer to this space made after pushing your partner away as "thinking space". This is very important because it stretches your opponent out and gives you room to move angle your hips.
Once I make that "thinking space" I move one of my feet to the back of my partner's knee. Then I take my free foot and place the top of my foot on the hip (please reference the video). Some people are concerned about ankle locks here. You will be fine for a number of reasons. Primarily because you your opponent has no isolation over the knee and secondly because you are controlling both of your opponents sleeves.
Once your feet are in place it is important that you angle your body. This is the most overlooked part of entering into X Guard. The knee scooping motion is the most important and if you angle your body correctly it becomes EXTREMELY easy. Make sure to reference the video to see what I"m talking about.
Once the knee does clear under your opponent's thigh it is time to bring the ankle up to the ear. Make sure that when you do this you do it by swinging your arm in a "raising your hand motion" and NOT by using your palm to grab the legs. If you do this correctly it should be very easy. If for some reason it is very hard you can stretch your partner with your legs before you raise your hand. Anything to make them light on that leg.
Choosing wether to lift or stretch your opponent is going to be based your body length, the length of your legs, the length of your opponent and how he/she has their weight distributed. There is no clear cut answer to tell you when you do what it is something that you learn from being in the position and experiencing the pros and cons of both of these options.
Once you have your partner stretched it's time to enter a sweep. In this video I specifically look at the Roll to Knee on Belly.
Once you have them stretched I like to feed the sleeve to the hand on the back side of the leg. This is easier than you would think but if you have problems doing it you can honestly skip this step. It's MUCH more dominating but requires more time. Again, a balance of control vs viability.
Once you feed the hand it's important to take the now free hand and grab the far collar of your opponent. This, coupled with the challenging of the base, will make it extremely easy to rotate your opponents back to the floor. You'll find that it is incredibly easy to do fast but takes some work if you want to do it slowly like I do in the video.
Once you get your thumb in that collar and you're ready to sweep, allow your training partners the opportunity to base their hand on the floor or they might face plant into the mat. Although you dont care about this (typically) in competition, it's important that all of our training partners can turn their heads the morning after training this technique. I highly recommend doing it slowly, even though it's more difficult, until you have the technique down.