Standardise AND Normalise I am new to machine learning. 
Does it make sense that my model works when I do both Standardise and Normalise? What does this say about my data? 

Or do I do have to select one or the other? My goal is to build a binary classifier which analyses CNNs and GIST features?
No, actually it doesn’t make sense to apply two scaling methods to your data simultaneously. Generally, I would suggest using standardization because it is more robust to outlier samples compared to normalization. Having removed outlier samples from your dataset, you can safely use normalization instead.