[Kuolema]

Hey guys,
I've googled this several times and have been unable to find an answer.
I'm trying to have my electric guitars fade out into an acoustic section, but everything I try sounds like shit, they really muddy things up.
I'm working in Reaper and I've tried using the volume envelope, as well as editing the files in Audacity, but have not been able to produce any results that I'm happy with.
Does anyone have any tips for doing things like this? Is there a special way to do it? I've heard plenty of songs that do it well, but I don't know how...

[Metal Man]

reverbs+delays?

[AngelCityOutlaw]

Would it be possible for you to upload a clip of this undesirable effect you're getting?

[Moseph]

If you're not happy with a standard level fade, you could try automating a downward sweep with a low-pass filter.