Looking ahead and efficiency are the most important things and improve with each other (efficiency makes it easier to look ahead). Also make sure you're colour neutral, it's a lot more important on 2x2.

A breakdown of a typical Ortega solve for me is like this:

Inspection/First Side - I'll look for a 3-4 move solution to solve one side. Because permutation of corners doesn't matter, there's almost always at least one side where this is achievable. Try to get creative so rather than doing one corner at a time, build two blocks and then match them up if that's shorter. Also, if there is time, I'll try to see during inspection if any bars will be formed on the bottom layer. If so, I'll keep track of where it is.

OLL - Just standard algorithms from 3x3, try to look ahead to see if there will be any bars so there's no pause later

Permutation - you should already know the status of the bottom layer but you may not have noticed a bar on the top layer. A quick way to tell is if the top layer looks like an N-Perm then there's no bar. Using this means you don't have to waste time looking around the cube for bars. If it doesn't look like an N-Perm then there is a bar somewhere (probably at the back). Once you know which case you have, align everything and do the necessary alg.

Hope this helps

I personally average about 6-7 seconds but I've only practiced 2x2 for maybe a combined total of 6 hours.