The cross seems to be one I keep getting popped with I've started to adjust my stance and work on my footwork a little bit more. So should I be pumping my jab at all times? Do I ever throw a cross without throwing a cross or is that just when there 100% open?
Well, as Vanuken points out there are allot of additional variables to really answer specifically or without watching or seeing you in a ring. But the short of it, the most likely reasons that a guy is vulnerable to the cross are
1. bringing your jab back low, cross comes over the top
2. advancing on an opponent without using head-movement or without using your jab to close the distance.
3. slipping or circling toward the cross side and keeping square at the shoulders with a wide guard
4. reaching for your shots when your just out of range, especially against a guy with a reach advantage
5. keeping your guard to open, i.e : when your gloves are up your leaving to much gap or are too square at the shoulders that your an easy target for the cross.
Circling toward/outside the lead is probably a good idea and if your forced back toward his right try to angle out of the range of his cross or clinch up and turn out so you can get circling back outside the lead, and YES absolutely keep your jab busy, especially when closing the distance. Also, be mindful of the cross and use the jab to deter him from throwing it or making him force it. In short, jab toward that cross hand and jab upward so it is not so easy to fire off that cross, especially if he is coming over your jab with it....... really, just be aware of the cross and knowing you get hit with it consistently work on trying to bait the opponent into throwing it, this way you expect it, or can anticipate it. The jab is an ideal way to do that as well.