After many years at this hobby, I would agree with a couple things mentioned above. I would also add something.
With any type of telescope with a corrector or lens in front, you need a dew shield. If you can afford a dew controller and heater get one. As one person above said, If your scope is outside, cold, and not dewed up, cap the end (lens/corrector) end. If there is a lot of dew on the tube, gently wipe it down before bringing in. Leave scope out of box, capped, and then check the lens after it has been indoors for at least an hour. (Or you can leave it to the next morning). Take the cap off and if you have any dew, use a hair dryer to evaporate it. Do not put the hair dryer on high or direct the heat directly (like an inch) from the lens. You will see any dew evaporate. Then recap and call it good. Do not put any type of cloth on the surface of a lens/corrector/mirror.
Eyepieces: When outside, see if they are fogged up, if not cap them and put them into your eyepiece case. You can use the same method as above after they have been in the house for awhile. Remove the caps, if you see any dew, use the hair dryer to evaporate. Again, do not use anything (like a hanky or rag on the surface. If you see eyelash oil on the lenses, wait until you have time and then use a small bit of alcohol to clean. Do not use acetone as it will destroy and plastic. Kimwipes to use gently (dab) on the surface with alcohol...do not allow any liquid to wick under surface of eye lens...going deeper, use reagent grade isopropyl alcohol (92+ percent you can get at a pharmacy) as the others leave streaks. Again, keeping dew off by evaporating is the best way and the air from the hair dryer will blow away dust/lint.
If you need to fully clean the optics, which should be no more than once per year, you can find several recommendations on how to do it and what to use...