Aggression isn't a simple, singular topic. Instead, it has multiple facets and factors, which means effectively ramping it up tends to be quite a bit more complicated than just doing A, B and C at pre-specified times.

For example, it's not uncommon to equate getting more aggressive to playing more hands. In many cases, getting more aggressive does involve playing more hands, but not necessarily so. It may be that you're playing enough hands, but in a manner that's generally weak and passive. That would probably mean you're not raising enough, not value betting enough, and not continuation betting enough.

One thing you can do to help raise your aggression is to look for situations where a reasonable aggressive option is available, but you normally don't pick it, and start picking it.