This depends on the value of "your" micronation for the larger nation of which it is a part. If your micronation is important to the larger nation, then creating it may be an effective means of making your point. If, however, your micronation does not mean much to the larger nation, you may well be hurting yourself more than you hurt the larger nation.
In addition, attempts at secession can often be met with violence. Larger nations are rarely willing to part with portions of their territory. If this happens, you have to ask yourself whether the political point you are trying to make is worth the bloodshed and destruction.
Overall, then, I would argue that secession is rarely the most effective way to make a political point.