The Best Quality is to Have Trust in Allah
Ibn Taymiyyah
"Each of you should ask for his needs from Allah, even if the strap of your sandal breaks, because if Allah does not facilitate it, it will never be possible."
As for the next part of the question, about the most valuable quality to aim for, then the answer to this is that the best prize is to have trust in Allah, reliance upon Him of His sufficiency, and keeping a good opinion of Him, the latter being that if anyone is anxious regarding their sustenance then he should turn to the shelter of Allah, as the Exalted said, from what is narrated by His Prophet, sallallahu 'alayhi wa sallam:
"O My servants, all of you are hungry except for those I have fed, so seek food of Me and I shall feed you. O My servants, all of you are naked except for those I have clothed, so seek clothing of Me and I shall clothe you." [Upon Abu Dharr, related by Muslim, at-Tirmidhi, and Ahmad]
In this regard there is also a hadith which at-Tirmidhi narrates from 'Anas, radiallahu 'anhu, who said that the Messenger of Allah (salallahu 'alayhi wa sallam) said:
"Each of you should ask for his needs from Allah, even if the strap of your sandal breaks, because if Allah does not facilitate it, it will never be possible."
Allah the Most High says in His Book:
" ... But ask Allah for His bounty ... " [Al-Qur'an 4:32]
"And when the prayer is finished, then you may disperse through the land, and seek the Bounty of Allah ... " [Al-Qur'an 62:10]
Although this ayah is in the context of the congregational Friday prayer, its meaning applies to all the prayers. That is why - and Allah knows best - the Prophet sallallahu 'alayhi wa sallam instructed the person entering the mosque to say:
"Allahummaftah li abwaba rahmatik." (O Allah! Open the doors of Your Mercy for me)
and when leaving the mosque to say:
"Allahumma inni as'aluka min fadlik." (O Allah! I ask of You some of Your Bounty)
[Muslim, Abu Dawud, an-Nasa'i, ad-Darimi, Ibn Majah, Ahmad, Abu 'Awanah, Abdur-Razzaq and al-Bayhaqi]
Also the Friend of Allah (i.e. Ibrahim, 'alayhis salam) had said:
" ... then seek sustenance from Allah, serve Him, and be grateful to Him." [Al-Qur'an 29:17]
This is a command, and a command signifies obligation. Therefore, to seek help from Allah and to entreat to Him in the matter of livelihood and others is a fundamental principle. Furthermore, it is important in seeking a livelihood that one should acquire wealth with generosity of heart and not with greed so that he may be blessed in it. Neither should he make the wealth the primary aim; rather, he should regard wealth much as he regards the toilet, which he has need of but it has no place in his heart, and he only resorts to it when necessary.
A marfu' (i.e. report consisting of a chain of narration that goes back to the Prophet, sallallahu 'alayhi wa sallam) hadith which is related by at-Tirmidhi and others states that, "He who begins the morning with this world as his greatest concern, Allah disperses his collected gains and puts its loss in front of him, and only that of the world comes to him which is written for him. And he who begins the morning with the Hereafter as his greatest concern, Allah gathers for him his works and creates richness in his heart due to them, and the world comes to him subserviently." [Related by at-Tirmidhi with a da'if isnad, but the hadith is sahih due to the supporting narrations of Ibn Majah, Ibn Hibban and Ahmad]
One of the salaf said, "Each of you is in need of the world, but you are in more need of your portion in the Hereafter. Therefore, if you are in search of your portion in the Hereafter first and foremost, then you will achieve your portion of the world in passing, such that it is taken care of as it comes."
Allah the Exalted says:
"I have only created Jinn and men that they may worship Me. No sustenance do I require of them, nor do I require that they should feed Me. For Allah is He who gives (all) sustenance, Lord of Power, Steadfast (forever)." [Al-Qur'an 51:56-58]