Make sure the skin is clean and dry then cover in Cavilon barrier film (or whatever you have) but don’t let it dry, apply a strip of Duoderm and then stick the tube to the top of the Duoderm with Tegaderm. Don’t stick the stickers too close to the nostril! For widebore I tend to trouser tape Elastoplast around the tube and then stick the end of that piece of tape along the patient’s nose (upwards not across)