There are a lot of factors that go into an invitation, and the recruiter's nomination is an important factor.
Some of the factors are outside of your control (programmatic changes, for example). Other factors, such as getting all of your paperwork in on time, responding quickly to requests for information, are within your control.
The best way to enhance your own chances of getting invited to the country that you've been nominated to is to continue building your skill set. Keep getting volunteer/work experience related to the program for which you were nominated, so that when you are compared to other candidates who have been nominated to the same program, you are as competitive as you can be for service.