Lecture time is a great time to practise pen-spinning. Of course, paying attention to the lecturer is important but at the same time your hands can be kept busy with spinning a pen when there are no notes to copy. This will also prevent one from falling asleep during lecture. Almost like killing two birds with one stone.
I downloaded a few of the gif files on pen-spinning I found on the Net. There are many more which I have not downloaded so you can look them up yourself if you are interested.
This is the normal spin I learnt in Sec 4. The gif is not that clear. But basically, for this style, the pen is first held between the third finger and the thumb. With the index finger out of the way, you apply force in direction towards thumb to spin it 360 degrees around the thumb. You then catch it with the index finger.
This is the sonic style which I learnt from bt last year - 1998. The gif shows the one-way sonic. It can be extended and the pen is moved back and forth without a break in between. This style takes observation and practice. It is not as difficult as it seems to be.
This is the style I am trying to learn at the moment. I can only do it pathetically slow. The successful version is where there is no break in between the forward and backward normal spins. The time interval is almost a split of a second.
There are a great number of styles and also variations of the basic styles. It takes time for one to master each of this styles well. Observation of others spinning pen is a great way of learning. Of course, the best way is to find the style you want and get someone who is great at it to teach you. Although that is not always possible but it certainly is the most effective way of learning.