Ephesians 6:18 says Pray at all times (on every occasion, in every season) in the Spirit, with all [manner of] prayer and entreaty. To that end keep alert and watch with strong purpose and perseverance, interceding in behalf of all the saints (God's consecrated people).
When it comes to prayer I have been both a giver and a very grateful receiver. Prayer is so vital to my well-being. I praise God, my heavenly father, that He is always available to listen to my prayers and He knows exactly what to do! In great contrast to myself, when our children want to ask me some things, I am not always available, and certainly I do not always know what to do!
Regarding praying for other people, sometimes it can be "obvious" what they need prayer for. Either through a specific request for prayer, or a conversation with them might reveal a circumstance that requires prayer.
Sometimes it is the whisper of the Holy Spirit in the middle of the night, or when I am hanging out the washing, that says, 'pray for this person'. In most instances nowadays I recognize the Spirit's voice. However I have no idea why or what to pray, so I immediately start to pray in the Spirit. Often once I start praying in the Spirit, a specific word, such as 'peace', or 'wisdom' will come to mind. I claim that word over that person's life, in Jesus Name. If it is a reasonable time of day, I might even text the person to say, "praying for you" and give them the word that God has given me for them.
When I next see the person I was prompted to pray for, it sometimes transpires that there was a need for prayer and encouragement at that specific time the Holy Spirit prompted me to pray. I get so excited when I hear that, as it reminds me how God can use us, if we make ourselves available to Him. What a network of support if we would have if we always listened and obeyed the promptings of the Holy Spirit to pray for others.
A couple of challenges for us all, are we available to hear the Holy Spirit? Are we being obedient to the promptings of the Holy Spirit to pray for those He puts on our hearts?