|Big class Friday - my teaching is still a work in progress|
1. Take notes on every position in which your situation worsened during regular sparring for a set period of time (a week or month depending on how often you train).
For example, you could not escape side mount, your single/double leg tackles are always getting stuffed, you are being passed easily by the bullfighter pass, etc, etc. The list can go on.
2. Give priority to the ones that happen the most or you are frustrated with.
3. Drill the position for a month then have a trusted partner do positional sparring with you slowly increasing the pressure.
4. Doing the same technique over and over again will get boring so associated 10% of the drilling session to techniques that you feel are "cool" or want to maybe develop but are probably low percentage for your body type or persona. i.e. In my case this would be flying armbars, berimbolo, imanari roll.
Don't just turn up at a drilling session without a plan and then follow what everyone else is doing or just think "Hey, x-guard is cool. Let me try some of that." Work on what you need but above all make it simple.
Drilling will help in the long run. I know it works because I've seen how judo is trained over here in Japan. The most important thing I believe, however, is sensitivity. If you want to improve a certain position then you have to jump right into it every round of sparring. Say you are working on spider lasso guard, get into the position each time and react to your opponent's movement. There will be times that you fail and he will pass but you must analyze it (don't forget to ask your rolling partner) so that next time you register that moving that way or going down that path will lead him to passing you. Chose a different option at that point and see how it works out. Sensitivity is about feeling. It's about knowing what will happen before it does. It's like having spider senses because you have been in that position so many times. This can't be taught to white belts, they simply have to go through their dues and experience it.