The following is to setup log4net in a console application. You will need to get the log4net Nuget package or reference a downloaded log4net dll.
//AssemblyInfo.cs
...
[assembly: log4net.Config.XmlConfigurator(Watch = true)]
//App.Config
<?xml version="1.0" encoding="utf-8"?>
<configuration>
<configSections>
<section name="log4net" type="log4net.Config.Log4NetConfigurationSectionHandler, log4net"/>
</configSections>
<log4net>
<root>
<!-- add other appenders here and the log messages will be sent to every listed appender -->
<appender-ref ref="LogFileAppender" />
<level value="ERROR"/>
</root>
<!-- The DebugFileAppender writes all messages to a log file-->
<appender name="LogFileAppender" type="log4net.Appender.FileAppender">
<file value="C:\\Projects\\Logs\\iFormBuilder.log" />
<appendToFile value="true" />
<lockingModel type="log4net.Appender.FileAppender+MinimalLock" />
<layout type="log4net.Layout.PatternLayout">
<conversionPattern value="%d [%t] %-5p %c %m%n" />
</layout>
</appender>
</log4net>
....
//Program.cs - or whatever files you have
var log4Net = log4net.LogManager.GetLogger(typeof(Program));
log4Net.Debug("Start logging.");