Being the complete opposite of HiFi, Lo-Fi (Low Fidelity) audio means you are lowering the quality of the sound. Meaning, instead of producing (or recording) audio that abides the usual standard for modern music, Lo-Fi producers deliberately let or add technical flaws flow through their tracks; we add distortion, hum, background noise, and/or limited frequency response.
In my case, I do that by sampling sounds from various songs dated back in the 20th century. I’ve also added a vinyl feel to it through the Vinilyzer plugin on FL Studio. On top of that, I used Ohmicide plugin to introduce distortion.