Capturing skylarks is actually very simple. The net trapping method is more efficient and is the most widely used method to capture adult birds in various places. The key to using glue to catch birds is to prepare the appropriate glue.
As for the capture time, it is best to capture it when it is just dawn and dusk. Don't catch them at noon. The birds will fly far away as soon as they see you at noon. But at dawn or dusk, they don't fly much and run in the fields. Skylarks are very easy to catch.