Visa letter of invitation might help you to visit other countries.
What to Include in the Letter of Invitation
This should be a personal document, not something like a lawyer would write, so don't stress over making it sound official. Make sure that you include both your and the recipient’s name and full address, for example using the format shown below.
Also be sure to cover:
the purpose of the planned visit, including what places you will visit
how long the visitor will be staying with you or where you've made arrangements for he or she to stay
Whether you will be covering the person's transportation to and from that countries, and
How much of the person's expenses in that particular country. If any, you plan to cover.
Be as specific and detailed as possible. Below is a sample letter for you to use as a guide.