Have the right visas, residency and work permits.
If you wish to obtain a permanent residence permit you will need to prove that you have funds in excess of R$500,000 ($150,000 / 135,000€), but even then this visa is only issued on a five-year conditional basis. In order to re-validate your visa you must show the Federal Police how you have invested in, and therefore improved, the local economy. However, if you are planning on employing Brazilian staff, whether in the home or workplace, then this initial investment figure may be reduced.
Meanwhile, if you are thinking of retiring to Brazil then you must be over 50 and receive a monthly pension of over $2,000 (£1,292) per calendar month. Of course, if you are only planning to stay in Brazil for short periods of time, then a tourist visa will suffice. Tourist visas forbid you from working, and you are only allowed to stay in the country for up to 90 days. You will also need to produce a return ticket on arrival.