Flights

"How far in advance?" Depends who you ask. I use miles to fly to Europe now (usually you need to book those long in advance, but this year I booked only a few months out for AA and Alaska award tickets to/from Portugal), but when I paid for plane tickets, I rarely booked more than two months in advance. I still wouldn't, unless I got an amazing fare.

But some people book long in advance, just to lock in a fare and think about something else.

At worst, go to Google Flights, find the ideal flights for you, and set a fare alert - Google will notify you if the price drops.

FYI, if flying to say Italy, try to book an "open jaw" ticket - fly into one city, out of another (maybe fly into Venice out of Rome or something). Don't book two one-way tickets; book it as a "multi-city" ticket. Doing this saves you the time of back-tracking in Europe just to fly home.

Thank you so much !!!

No simple answer. Best practice (for paid flights) seems to be: You need to invest some of your time and effort to have the best chance of getting a good flight at a good price. Start monitoring fares now, be patient, watch as flight prices go up and down, learn the range within which they tend to fluctuate. Also, don't just be hypnotized by price alone, obsessing over saving a few bucks at the expense of a miserable, sub-optimal experience. Factor in whatever you care about, including price, but also relative comfort (or lack thereof), good routing/connections, and above all know exactly what you are about to pay for ("beware things like "basic economy", crazy routings, horrible/multiple connections, long layovers, super-cramped seats, etc.). When you see a flight that you think is good for you, jump on it. Once it's booked, don't look back.

I troll constantly for great airfares, and it depends on the prices at the time. I most often buy 3-4 months out.
If you're flying out of NYC, you're in luck because Norwegian Air Shuttle is flying into NYC airports, including the Stewart Airport an hour north. It all depends on where you're flying to.
My last flight into Stewart from Dublin was $158 in April, 2018, for example.
I suggest you check out Norwegian.com.

What works for me in flyover country with limited options and no budget carriers is to think the obvious and not so obvious flight possibilities many months out and use different days of the week as well. Logic and airfares don’t always match. Also, fares here tend to rise as proposed dates approach and availability of connecting flights tend to shrink, so buying months out is the norm. Smug travel writers trying to extend their careers, don’t live near me and thus, offer humor rather than solid advice.

I enter flight alerts on Google Flights and Kayak and when I see a low fare, I book it. Right now watching for April flights to Tokyo. It hasn’t budged at all yet.

I generally go in late June/July, the most expensive time. Just bought the tickets now, but generally I buy 5 to 6 months in advance. According to a study by CheapAir, prices are lowest around 5 to 8 months out, but you never know. Sometimes you can find deals much closer to the day of departure.

The cheaper days of the week to travel are midweek. Friday and Sunday the most expensive. You willl probably save a bit if you avoid leaving on Friday and choose Thursday before or Saturday instead. Wednesday is statistically the cheapest day to fly to Europe, if you have flexibility.

The time of the year you go counts the most. Summer is the most expensive season, during which July is the most expensive month to fly. June comes second. Before the second week of June and after the first week of August prices are a bit lower. January to March is the cheapest of all.

I just purchased (yesterday) 2 tickets from JFK to Rome for $702 in basic economy on British Airways. Travel dates are April 28 outbound and May 11 return. You can use Google flights to look for other dates and cheap fares.