As mentioned in the Snowhead Temple guide, now is the time to get the Gilded Sword before you move on. The jump in damage output from your Kokiri Sword to the Gilded Sword is much worth the effort. As opposed to the Woodfall Temple, however, collecting all of the Stray Fairies from Snowhead is not crucial to success. It just nets you a more powerful Spin Attack. If you want to do it for completion’s sake, go ahead, but you can definitely give it a skip if you so desire.
Also, it would be recommended to grab Romani’s Mask from the Romani Ranch subquests. To get it, you have to protect the ranch from aliens on Day 1, and then protect Cremia’s cart from the Gorman brothers on Day 2. Then, you will receive Romani’s Mask. It provides a dual bonus of giving you access to the Milk Bar after 10 PM as well as making you look like a cow (though only the former is important). At the Milk Bar you can fill your bottles with regular Romani Milk for 20 Rupees per bottle, or Chateau Romani for 200 Rupees per bottle. Chateau Romani is expensive, but worth it– after drinking it, you get infinite magic power for the current three day cycle you are on. Since Zora fast swimming relies on your magic power, having infinite magic power allows you to swim as quick as you want.