我做整咗杯牛奶𠸎同埋加咗少少花蜜落去。

You can put the word 咗 after the verb 整&加 to express the past tense.

use the verb 整 for food instead of 做, for example, 整咗個沙律 made a salad

Great said from Kai Ling. Here is another way to say:

我整咗杯奶，加咗啲蜜糖 / 蜂蜜落去  I made milk with a little honey in it.

For native speaker, we usually say 杯奶 rather than saying full phrase of 牛奶。Cantonese can be lazy to use short form :)
花蜜 and 蜂蜜 are the categories under 蜜糖. I would say 蜜糖/蜂蜜 makes more sense on milk to me as I think 花蜜 is more watery and more for tea. 
Besides, you can also use 啲，which is same as 少少。