Previous observing, you can be interested in determine the WYFFOS focus (see Ref.: INT-IAC-TRP-009 for details). In order to do it, you can use int_hart. And you can obtain arc lines FWHM with int_fwhm for the best focused image.
During observing you can use int_rec to perform a reconstruction image of your object. And get some of their spectra with int_nspec. These are very useful in order to verify the observed field, the characteristic of this field, the emission and absorption features, or the data quality (signal to noise).
Likewise, with int_daref you can determine the different wavelenght continuum maxima shifts produced by the differencial atmospheric refraction.
And can verify the stability of the system with int_spd1f and/or int_spdXf.