I would only give a favor that they can do something with, like eat it. Otherwise, most of those will go to waste, especially for something like a reveal party. While it's a good time to get together with friends and family, I doubt it's a memorable event for most people, except those directly involved.
Me: 38 DH: 36 Married 8/27/2011 BFP #1 9/28/2011 DS born 5/22/2012 BFP #2 4/24/2013 m/c 4/25/2013 at 4w BFP #3 1/31/2014 DD born 10/14/2014 BFP #4 1/20/2016 m/c 2/12/2014 at 7w2d BFP #5 8/19/2016 DS2 born 4/29/2017 BFP #6 3/7/2018 EDD 11/18/2018
Re: throwing a gender reveal party
Married 8/27/2011
BFP #1 9/28/2011 DS born 5/22/2012
BFP #2 4/24/2013 m/c 4/25/2013 at 4w
BFP #3 1/31/2014 DD born 10/14/2014
BFP #4 1/20/2016 m/c 2/12/2014 at 7w2d
BFP #5 8/19/2016 DS2 born 4/29/2017
BFP #6 3/7/2018 EDD 11/18/2018