Formal — to staff
Ramen · Shop · Ticket · Machine
You
すみません、この食券機の使い方が分かりません。おすすめは何ですか？
すみません、このしょっけんきのつかいかたがわかりません。おすすめはなんですか？
Excuse me, I don't understand how to use this ticket machine. What do you recommend?
Romaji: Sumimasen, kono shokkenki no tsukai-kata ga wakarimasen. Osusume wa nan desu ka? / Reply Romaji: Kochira ga ichiban ninki desu yo. Sōsa o otetsudai shimashō ka?
Reply
こちらが一番人気ですよ。操作をお手伝いしましょうか？
こちらがいちばんにんきですよ。そうさをおてつだいしましょうか？
This one is the most popular. Shall I help you with the operation?
Gesture & etiquette
Point to the ticket machine with an open hand, then make a questioning gesture with an open palm for 'recommendation'.
Avoid taking too long at the machine if there's a line. Be ready to accept the recommendation or point to something on the machine if possible.