Exodus 28

2 God commanded the high priests to wear extravagant clothing. This was to distinguish them and to remind the people of the glory and beauty that God had.
3 God indicated that there were particular artisans that He had filled with wisdom. We would say that these people were "inspired." God gives each one of us "wisdom" in one or more areas, and God wants each one of us to use that "gift" to honor Him. If you are not using your gifts in some way to honor God then talk with your minister. If everyone contributed, the community and the Church would be strengthened, and God would be glorified.
11 God is symbolically telling us how much He valued the people of Israel -- as gemstones in gold settings.

Signet stones were used to sign and seal important documents. The artisans were to make the stones like signets to show that the Israelites were the authority and signature of God.

12 The names on the gemstones were to remind the Israelites of who they were and where they came from. After the breakup of Israel these stones served as a sad reminder to what happens when people start become more interested in themselves than in God or their community.
15 A breastplate for soldiers was made of leather and metal. The breastplate for the high priest was made of fine cloth.
21 God sees Israel as precious, but He also emphasizes that each tribe is precious. We must remember that God does not just see us as the Church, but He sees and cares for each one of us. Each of us is an image and authority bearer of God. We must make sure to take these responsibilities seriously.
29 Notice that the high priest wears the breastplate of judgement before the mercy seat.
30 Not to be misleading, "judgement" here does not necessarily have a negative meaning here. God indicates that He will not speak directly to the high priests as He was speaking to Moses. In conditions where the priests needed a clear answer from God they would take out the Urim and Thummim and receive God's answer (i.e., judgement) through them. We do not know what these objects were or what they looked like, or even how many there were. Some have suggested that they were the twelve stones described previously (TSK). But the twelve stones were mounted in settings (Exo 28:17) and this verse makes it clear that the Urim and Thummim were placed inside the breastplate. They must have been more complicated than mere dice since a variety of answers could be received through them. They could be used to give directions (Num 27:21), pick tribes (Judg 1:1), answer yes and no questions (1 Sam 23:9-12), or may not give any answer at all (1 Sam 28:6). God makes it clear that these are not objects of superstition, but would serve to communicate His wishes when needed. Because these objects are not described, they could not be copied for fraudulent use.
31 Blue fabric symbolized royalty. The priests participated in serving the King of kings.
32 Garment makers and quilters recognize this as binding. This was important to keep the clothing from unraveling and diminishing its beauty.
33 The hem had decorations around it. The pomegranates were possibly made of knotted thread.
35 God knows everything, so the purpose of the bells can not be to warn Him of the approaching priest. But even if we don't know the exact function of the bells in the Day of Atonement rituals, we do know that God commanded it, and explicitly warns that if a high priest breaks even this small command he will die.
36 The high priest was to wear a crown that declared that he was set apart for God's work. As Christians, we too are to be set apart for God's work, but we should show that by our words and actions, not just by wearing a cross (taken as a parallel to the crown here). Remember that the high priest wore this crown, but he also had to do the work.
38 The high priest would carry the sins of Israel before God once a year, and the crown was a symbolic part of that. When Jesus came before God He carried the sin of the entire world and the crown of thorns is a symbolic part of that.
41 Aaron's family was not elected, nor did they volunteer for the priestly duties. God appointed them to do so, and it was their duty to obey. Similarly, God has made all Christians into a kingdom of priests. It is our duty to obey that calling by sanctifying our lives and telling others about God.
42 Similar to boxer shorts, the underwear would prevent the priests from revealing themselves while they served at the altar (Exo 20:26). The implication is that it was uncommon for men to wear undergarments under their robes.