Honest question (I've never used Last.Fm):
Do these suggestions show up in MusicBee?
Do you get them from LastFm's website after you've logged-in?
There are plugins for MB (don't know if they're integrated at this point because I've always had them). One is a last.fm playlist generator, which will generate a playlists from your library of a genre, or tracks related to either the selected track or the artist of a selected track as tagged at last.fm (not your tags). Good for folks less focused on tagging their genres.
There is also a last.fm recommendations plugin that enables a tab with a bio of the playing artist, similar artists to the playing artist, and tracks similar to the playing track.
What I mainly do, though, is go to the last.fm recommendations tab when something playing really strikes me and click the "read more on last.fm" link for the artist. That brings me to the artist's page there, with lists of similar artists, tracks and albums by the artists rated by listenership. Each artist has user generated tags where I can explore more from the broad categories that the artist belongs to. If I go into one of the listed songs, there are lists of similar tracks.
Besides the manual artist tagging, which are people's judgement calls, it's crowd-sourced recommendations based on what people actually listen to. People who listen to A also listen to B.
Once you build up a large "library" of listened tracks, the artist, track and album recommendations from the home page become quite focused on your tastes.
There are also premium features for paid users. I am not one, but I have considered it at times.
A smile is happiness you'll find right under your nose.