Taking bases requires 2 things as its most basic:
1. Innate knowledge and experience of the offender(s): The person attacking needs to know where in the base defenders camp and have a good knowledge of what weapons they need to have (commandeering re-supplies from the enemy base is an excellent strategy for offenders once you get good at it), what approach they need to take, and where to look at they move into a base. It also helps to have enough map awareness to know where the majority of the enemy team is, where they are spawning, and in what direction they are moving from spawn.
2. The base in question should not be an enemy spawn base: Ideally, you want to take the backside (least defended) base from the enemy when they own 2 bases. Taking a base in which enemies are constantly spawning in close proximity to is extremely hard to do and I have come to the conclusion that is it almost impossible to do against an equally skilled party without any combination of the following 3 points:
-Strong vehicle support
Because of how much your team must commit to take a spawn base from the enemy team, your own base(s) are often pulled out from under you as the displaced spawning enemies begin spawning in neutral spawns with access to your mostly unguarded base(s) This is why most dominion veterans are in agreement that simply caputuring and holding 2 bases is easier than trying to take the enemies' last base from them.
If you think we're a rolling double kill.. come get it.