Give them full hugs some need a kiss too. Get a half hearted I'm good tell them look me in the eyes and say that then ask what's up do you need to talk.
We must use scriptures when giving encouragement.
James 3:16,17 "16 Do not be misled, my beloved brothers. 17 Every good gift and every perfect present is from above, for it comes down from the Father of the [celestial] lights, and with him there is not a variation of the turning of the shadow." So anything that brings joy to their hearts is Jehovah reminding them he loves them. Tell them to splurge on themselves is a gift of the happy God. Fathers give their children presents so does Jehovah & his Son. Remind them behaving like a Christian is service to God
Remind ones Jehovah & Jesus is the only one who knows how hard they try and they see. When ones feel bad about service tell them they did their best and to remember it's supposed to be a great crowd no man was able to number so don't get hung up on the numbers remember Jehovah and Jesus know their motives.
2 Cor 8:12 "For if the readiness is there first, it is especially acceptable according to what a person has, not according to what a person does not have."
Gal 6:3,4 "3 For if anyone thinks he is something when he is nothing, he is deceiving his own mind. 4 But let each one prove what his own work is, and then he will have cause for exultation in regard to himself alone, and not in comparison with the other person. 5 For each one will carry his own load."
1 John 3:19-22 19 By this we shall know that we originate with the truth, and we shall assure our hearts before him 20 as regards whatever our hearts may condemn us in, because God is greater than our hearts and knows all things. 21 Beloved ones, if [our] hearts do not condemn [us], we have freeness of speech toward God; 22 and whatever we ask we receive from him, because we are observing his commandments and are doing the things that are pleasing in his eyes.