Of course! Free presets are much welcomed in FH.
To use them and 'ave others see them, place the downloaded preset files in the correct My_Presets' folder. The correct folder will be the one with the corresponding number. (Say the head image ye downloaded is named preset_6head.png, then place the files in Preset_6 folder.)
Once placed, start up the game and enter y'er username in the correct box. Head to Tools and select Preset Maker. The Preset_6 (or whatever the numbered preset is) should show up in y'er list of presets. Simply select the preset and click export. Now that ye got the exported preset file, which should be y'er name and an underscore after it with the corresponding number, upload it to a download site like Mediafire or Dropbox. All there is to do now is hand that link to the download out to y'er friends f'er them to download!
Hope this helped ye. If ye 'ave any questions or need me to explain further, I'd be happy to assist!