Combining attacks from mount
A very fundamental martial arts skill is attacking your opponent where they are not defending. In stand up striking arts this is often accomplished by feints. The objective of a feint is to encourage your opponent to open up their defense and defend one attack, leaving them open to a different attack. In Jiu Jitsu this is accomplished by using double attacks.
A classic example of a double attack is the cross collar choke and armbar from mount. In striking arts you more or less have to defend feints and real attacks similarly. You can't wait to see if a feint is actually a strike intended to do damage. In Jiu Jitsu though an experienced practitioner can easily tell the difference between a legitimate threat and a poor attack.
That is why it is essential to spend plenty of time working on the details of each individual attack. All the little details that go into the cross collar choke are what makes your partner HAVE to defend it. When you threaten with a legit choke your partner will most likely expose their elbows which opens up the armbar.
Common pitfalls in mount attacks are:
1) losing focus of position because you are too focused on the submission
2) Trying to add more moves in to the mix before developing proficiency with the basics
3) Trying to attribute, (speed, strength) your way through poor technique
Gavin does a fine job of explaining the details of the double attack from mount in the videos below. A previous example we covered in class was the Ezekiel choke setting up the armlock.