special effects

over the christmas holidays i've been thinking of ways to improve my final product to the best of its ability. I already have perfect vision of the direction my product is heading in however, i wish to improve it in the best possible way to get the best outcome for my product. now, I am considering using special effects. The reason I will be using special effects is that if I will be able to pull off a special effect in my final product my grade will go up a fair amount also will make the film more realistic. However, in my final product there really is no need to use any special effects. Therefore, i'm trying to work out is it worth it. Because it could potentially ruin my product and make the outcome not look realistic.