This is generalized prediction and whole chart needs to be analyzed including D1and D9.

Many people have mentioned some common nakshtras if you have this you get beautiful or stunning spouse

1. Chitra or Rohini is most commonly said by many astrologers whenever your 7th lord, Venus or dharakarka is connected to them you get very beautiful/Stunning  spouse
2. whenever your 7th lord or Venus or dharakarka is in moon nakshtra you get sweet , cute or emotional spouse
3. whenever your 7th lord or Venus or dharakarka is in Venus nakshtra you get beautiful/pretty and romantic spouse
4. whenever Venus/moon sits in 7th house spouse is beautiful
5. Mercury in 7th house gives youthful looks to partner

6 some people also mentioned Venus should have some afflictions as well like Venus + Mars gives sex appeal or Rahu Venus gives ethereal unique or magnetic looks. People also mentioned Venus + moon gives beauty of feminine nature.  
7 But also what happens when you have combinations of those in your chart like 7th lord/ Dharakarka connected to chitra nakshtras Venus In Venusian nakshtras etc?  
8 if your upadapada lagna 1st house has either Venus or moon you get a beautiful spouse  
9 some also mentioned 8th house of D1 if you have Venus or moon your spouse face is beautiful.  
10 Many have mentioned debilated Venus gives a very beautiful or stunning spouse.  
Question is what happens when the person has multiple of these combination is the beauty increases or the probability of getting a stunning spouse?

Beautiful Spouse Yogas