i used Willybach's pack before. it's okay... but there is a HD pack that, (IMHO), is waaaaaay better than Willy's.

https://www.nexusmods.com/valheim/mods/1620

download the optional files as well for grass tweaks, and the killer reshade.

and dont forget HD Skies:
https://www.nexusmods.com/valheim/mods/1593

and you'll get some TRULY amazing visuals.