plain sailing

be (all) plain sailing (easy after being difficult to begin) — легко, гладко; ≅ (дальше все) как по маслу

Example 1: Well, the first three months in China were quite hard, but after that it was all plain sailing.

Example 2: I was so tempted during the lunchbreak, but I managed to get through the whole day without a cigarette, and after that it was plain sailing.— ... мне удалось продержаться без сигрет весь день, а уж дальше все пошло как по маслу. ()

Example 3: lt's a bit complicated to get to my house, but once you get out of the city and onto the motoway it's plain sailing. (Inn-4)

it will be (all) plain sailing — все пойдет, как по маслу
Related vocabulary:
[без сучка, без задоринки]
[it'll be all right on the night]
[as easy as pie]
[piece of cake]
[walk in the park]
kid (kid's) stuff;
to run smoothly
duck soup,
[cinch]