Carrying on with our "4 TOP TIPS" series, I would give you some quick tips about compression. Compressors are typically used to tame the dynamic range of an instrument, but they are also used to add texture to a sound or to shape it. Let's see some tips.
1 Try not to compress every instrument
Don't put a compressor on every instrument only because you can do it. A good rule of thumb is to analyze the instrument you're working on and then take the action needed. Does the voice sound dynamically uncontrolled? A compressor might work well. Does the kick need more attack and punch? A compressor might do the job. Does the guitar sound uncontrolled? Yes/no...take the action required.
2 Main instruments
There are some instruments that 90% of the time need compression. These instruments are Kick, Bass, and Vocal. I would say 90% of the time because it's always good to analyze the instrument before treating it. If you have a programmed kick probably its dynamic is already well-controlled, but you might want to compress it to shape its sound or give it a particular texture.
3 Two is better than one
Well, this is not always true. But, especially if you mix ITB and if you need a lot of compression, two compressors back-to-back, with less gain reduction each, work much better than one doing the whole job. Set one compressor to tame the peaks (fast attack and fast release) and another compressor to manage the overall dynamic (medium-slow attack, medium-slow release). N.B. These are starting points. Always use your ears to tune the compressor appropriately.
4 Help the compressors
If you are in need to dynamically control an instrument, consider automating/leveling its volume manually. To do so, you can put a gain/trim plugin on one insert and automate it increasing the volume of the lowest parts and decreasing the volume of the loudest parts. This will reduce the dynamic range, and the compressor will have less work to do to level the dynamic. As you can imagine, the compressor will go right after the gain/trim.