In Jesus's service. For His sake/purposes/benefit. (This is naturally for my own maximum personal benefit. Rom 8:16-18)

When my request is for strength, protection, riches or anything else to be used in the service of the Saviour, then I can legitimately say I am asking in the name of Jesus Christ. (Am. Heritage Dict: name)

If I am asking with an eye to my own comfort, luxury or glory, then my prayer is not in the name of Jesus Christ (1 Cor 13:1-3.) Closing a luxury-lusting prayer "in the name of Jesus Christ" is, in my view, a form of taking the name of the Lord in vain. (Jms 4:3; Exo 20:7) This is not wise.

I have found it very fruitful, and the Spirit confirms to me that it is right, to think "am I using this in the service of Jesus Christ"" before saying "in the name of Jesus Christ."