The focus of worship is God, but let's be more specific. A focus on God implies the following.
The focus should not be on us - our preferences. One song has about a dozen lines starting with "I just want to/I don't want to" - noble intentions no doubt, but Sunday morning is not the time to tell God and others what we want.
The focus should not be on us - our wretchedness. We certainly thank God for saving us from our former wretched state. But the focus should be on what God has done, not what we were. In the well known hymn Amazing Grace, the author John Newton rightly calls himself a wretch (he was not deceived into having self-esteem!) but the focus is on God's grace, not his wretchedness - good worship.
The focus should not be on us - our glory. In 1 Corinthians 11:3 we find that the head of the man represents Christ, and therefore, the man's head should be exposed (1 Corinthians 11:7). On the other hand, the woman's head and hair represent man and her glory, and so should be covered (1 Corinthians 1:11, 13). Note that Paul's reasoning has nothing to do with culture. The liberal Corinthian culture allowed women's heads to be uncovered, and Paul's Jewish culture demanded male heads to be covered.
There are many things other than female hair that can be flaunted (music, clothes, devices, jewelry, etc). If we flaunt things, we are ruining our Sunday morning.
The two great themes of scripture are creation and redemption. The Israelites were asked to worship on the Sabbath (Exodus 20:8, Exodus 31:17) which was meant to commemorate creation. But the apostolic practice was to worship on Sunday (Acts 20:7), the day when the resurrection was revealed. Jesus asked us to remember his death and resurrection through the Lord's Supper (1 Corinthians 11:25). Thus, Old Testament worship focuses on creation (as you can also see from a cursory reading of Psalms), but New Testament worship should emphasize redemption. Since redemption is in view, and since this redemption was obtained at great cost and suffering of our beloved Lord, New Testament worship is solemn. The Passover meal included bitter herbs and unleavened bread (Exodus 12:8); so it was not a "fun thing". Similarly, when we remember our passover Lamb (1 Corinthians 5:7), things are not hunky dory.