Filters are an incredibly powerful mixing technique to manipulate sounds, and this production method is found in a huge, diverse range of genres. From indie, to hardcore EDM, to lofi hip hop, filters are used to shape the sonic output within a track.
Simply put: High pass filters is a type of EQ that cut frequencies below a specified cutoff point.
Below is one of the best free filter VST plugins available that will give you professional sounding results without spending a dime.
Brainworx bx_cleansweep V2
This plugin is super smooth, very transparent and easily shapes your sounds (mono) and (stereo) to the perfect position in order to achieve more of a full sound. Almost 3D like. Download bx_cleansweep V2 for free here.
Watch this Video Tutorial
These are just starting points, adjust accordingly to your project needs.