This patch make Xfce use "gnome" as the default icon theme and enable font antialias.

Taken from ArchLinux.

diff -upr xfce4-settings-4.12.0.orig/xfsettingsd/xsettings.xml xfce4-settings-4.12.0/xfsettingsd/xsettings.xml
--- xfce4-settings-4.12.0.orig/xfsettingsd/xsettings.xml	2015-02-24 03:33:11.000000000 +0200
+++ xfce4-settings-4.12.0/xfsettingsd/xsettings.xml	2015-03-01 09:52:24.376869688 +0200
@@ -6,8 +6,8 @@
 <?xml version="1.0" encoding="UTF-8"?>
 <channel name="xsettings" version="1.0">
   <property name="Net" type="empty">
     <property name="ThemeName" type="empty"/>
-    <property name="IconThemeName" type="empty"/>
+    <property name="IconThemeName" type="string" value="gnome"/>
     <property name="DoubleClickTime" type="int" value="400"/>
     <property name="DoubleClickDistance" type="int" value="5"/>
     <property name="DndDragThreshold" type="int" value="8"/>
@@ -19,9 +19,9 @@
   </property>
   <property name="Xft" type="empty">
     <property name="DPI" type="empty"/>
-    <property name="Antialias" type="int" value="-1"/>
+    <property name="Antialias" type="int" value="1"/>
     <property name="Hinting" type="int" value="-1"/>
-    <property name="HintStyle" type="string" value="hintnone"/>
+    <property name="HintStyle" type="string" value="hintfull"/>
     <property name="RGBA" type="string" value="none"/>
     <!-- <property name="Lcdfilter" type="string" value="none"/> -->
   </property>
u/packages/fcitx.scm?id=85ba5e9335207beef9a650e96d5d64787beb9256'>diff</a></td><td class='form'><form class='right' method='get' action='/guix/log/gnu/packages/fcitx.scm'>
<input type='hidden' name='id' value='85ba5e9335207beef9a650e96d5d64787beb9256'/><select name='qt'>
<option value='grep'>log msg</option>
<option value='author'>author</option>
<option value='committer'>committer</option>
<option value='range'>range</option>
</select>
<input class='txt' type='search' size='10' name='q' value=''/>
<input type='submit' value='search'/>
</form>
</td></tr></table>
<div class='path'>path: <a href='/guix/log/?id=85ba5e9335207beef9a650e96d5d64787beb9256'>root</a>/<a href='/guix/log/gnu?id=85ba5e9335207beef9a650e96d5d64787beb9256'>gnu</a>/<a href='/guix/log/gnu/packages?id=85ba5e9335207beef9a650e96d5d64787beb9256'>packages</a>/<a href='/guix/log/gnu/packages/fcitx.scm?id=85ba5e9335207beef9a650e96d5d64787beb9256'>fcitx.scm</a></div><div class='content'><table class='list nowrap'><tr class='nohover'><th class='left'>Age</th><th class='left'>Commit message (<a href='/guix/log/gnu/packages/fcitx.scm?id=85ba5e9335207beef9a650e96d5d64787beb9256&amp;showmsg=1'>Expand</a>)</th><th class='left'>Author</th></tr>
<tr><td><span title='2020-09-22 11:02:58 +0200'>2020-09-22</span></td><td><a href='/guix/commit/gnu/packages/fcitx.scm?id=7e463dd16b7e273011f0beafa57a89fa2d525f8b'>gnu: fcitx: Update to 4.2.9.8.</a><span class='msg-avail'>...<span class='msg-tooltip'>* gnu/packages/fcitx.scm(fcitx): Update to 4.2.9.8.

Signed-off-by: Mathieu Othacehe &lt;othacehe@gnu.org&gt;
</span></span></td><td>Zhu Zihao</td></tr>
<tr><td><span title='2020-08-18 22:54:06 +0200'>2020-08-18</span></td><td><a href='/guix/commit/gnu/packages/fcitx.scm?id=d3ed745e4704fba1ef74c95363acd9a3f99b88f7'>gnu: Add presage.</a><span class='msg-avail'>...<span class='msg-tooltip'>* gnu/packages/fcitx.scm (presage): New variable.

Signed-off-by: Danny Milosavljevic &lt;dannym@scratchpost.org&gt;
</span></span></td><td>Raghav Gururajan</td></tr>