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>
0b6a343c5f64a3b4'>diff</a></td><td class='form'><form class='right' method='get' action='/guix/log/tests/zlib.scm'>
<input type='hidden' name='id' value='8d3167fe2399656d62d72c280b6a343c5f64a3b4'/><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=8d3167fe2399656d62d72c280b6a343c5f64a3b4'>root</a>/<a href='/guix/log/tests?id=8d3167fe2399656d62d72c280b6a343c5f64a3b4'>tests</a>/<a href='/guix/log/tests/zlib.scm?id=8d3167fe2399656d62d72c280b6a343c5f64a3b4'>zlib.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/tests/zlib.scm?id=8d3167fe2399656d62d72c280b6a343c5f64a3b4&amp;showmsg=1'>Expand</a>)</th><th class='left'>Author</th></tr>
<tr><td><span title='2019-04-16 17:30:22 +0200'>2019-04-16</span></td><td><a href='/guix/commit/tests/zlib.scm?id=b2c3640d2baa7bc929bf21880e6fb2785f5997f6'>tests: Gracefully skip zlib test when zlib is missing.</a><span class='msg-avail'>...<span class='msg-tooltip'>* tests/zlib.scm: Use 'test-skip' instead of (exit 77)
when (zlib-available?) returns false.
</span></span></td><td>Ludovic Courtès</td></tr>
<tr><td><span title='2017-10-11 15:20:50 +0200'>2017-10-11</span></td><td><a href='/guix/commit/tests/zlib.scm?id=85a2b58987bc32e33e63bea86c1a94496b796ae9'>zlib: Fix memory leak due to revealed ports not being GC'd.</a><span class='msg-avail'>...<span class='msg-tooltip'>Fixes &lt;https://bugs.gnu.org/28784&gt;.

This mostly reverts 81a0f1cdf12e7bcc34c1203f034a323fa8f52cf5, which
introduced a regression: revealed ports are *never* GC'd (contrary to
what Guile's manual suggests).

In addition to the revert, 'close-procedure' now explicitly swallows
EBADF errors when 'close-port' is called.

* guix/zlib.scm (close-procedure): New procedure.
(make-gzip-input-port)[gzfile]: Use 'fileno' instead of 'port-&gt;fdes'.
Use 'close-procedure' instead of 'gzclose'.
(make-gzip-output-port): Likewise.
* tests/zlib.scm ("compression/decompression pipe"): Use 'port-closed?'
to determine whether PARENT has been closed.
</span></span></td><td>Ludovic Courtès</td></tr>
<tr><td><span title='2017-03-15 15:19:53 +0100'>2017-03-15</span></td><td><a href='/guix/commit/tests/zlib.scm?id=81a0f1cdf12e7bcc34c1203f034a323fa8f52cf5'>zlib: Don't rely on EBADF being ignored by 'fport_close'.</a><span class='msg-avail'>...<span class='msg-tooltip'>In 2.2, 'fport_close' no longer swallows EBADF and instead raises a
'system-error' for this.  This commit adjusts for 2.2.

* guix/zlib.scm (close-procedure): Remove.
(make-gzip-input-port): Use 'port-&gt;fdes' instead of 'fileno'.
Use 'gzclose' instead of 'close-procedure'.
(make-gzip-output-port): Likewise.
* tests/zlib.scm ("compression/decompression pipe"): Don't check whether
PARENT is closed using 'port-closed?'.  Instead, use 'seek' on the
underlying FD and check for EBADF.
</span></span></td><td>Ludovic Courtès</td></tr>