I grew up Baptist, but am now a Presbyterian (PCA). Here is what I can think of off the top of my head. Please note that when describing Presbyterians, I am describing PCA (the more conservative branch) not the PCUSA (more liberal branch). The PCUSA is very broad in their beliefs and practices.
Church Goverment - Baptist churches usually have a pastor and a deacon board. When it comes to things that affect the entire church body, the entire congregation will vote on it. Presbyterian churches have Elders and Deacons. The pastor is one of the Elders. The entirety of the elders and deacons makes up the Session. The Session votes on things, not the congregation (except for voting for elders and deacons).
Baptism - Baptists believe that only those who have professed faith in Christ should be baptised, and that this baptism is only to be done through immersion (dunking). Presbyterians baptize those that have professed faith in Christ and the infants born into a Christian family. Baptism is viewed as a replacement for circumcision. It identifies you with Christians, just as circumcision identified people as Jews in the Old Testament. Just as a Jewish child would be circumcised, and then when he was old enough, he made his own decisions about his beliefs, Presbyterians will baptize their infants, but when they grow older, the person is responsible for where they put their faith.
Creeds/Confessions - Southern Baptists hold to the "Baptist Faith & Message" as their doctrinal statement. Presbyterians hold to the Westminster Confession of Faith.
Church service - Baptist churches vary quite a bit in what their service is like. It can be very quiet and subdued with just a piano, or upbeat with a full band/orchestra. Usually there aren't any times during the service that the congregation recites anything together out loud. In Presbyterian churches, the service is more liturgical, with corporate prayers (where everybody recites the same prayer out loud), reciting the Apostle's Creed, and responsive reading of Scripture. Most Presbyterian churches I have been in have had either just piano & organ accompaniment or piano, organ, orchestra, and acoustic guitar.
Free Will vs God's Sovereignty - Most Baptist churches shy away from Reformed Theology (Doctrines of Grace, 5 Points of Calvinism) and focus on man's "autonomous" free will, although the Founders wing of the Southern Baptist Church and the Reformed Baptist churches hold to Reformed Theology. All PCA churches hold to Reformed Theology as it is explicitly taught in the Westminster Confession of Faith. This causes more of a focus on God's Sovereignty.
Communion - Baptists use only grape juice, Presbyterians use either grape juice or wine.
Alcohol - Most Baptists are very opposed to alcohol and hold either a prohibitionist view (all drinking of alcohol is wrong), or an abstentionist view (drinking alcohol isn't necessarily wrong in and of itself, but we should abstain for testimony's sake). Presbyterians tend to hold to the moderationist view (As long as it is done in moderation, there is nothing wrong with drinking alcohol). Last month, my church had a men's ministry theology study at an Irish Pub.
Origin of the world - Baptists always teach literal 7-day creation. Presbyterians either teach that or teach a form of Theistic Evolution (God created using evolution), more specifically the Literary Framework view.
Rapture - Baptists usually believe the rapture will be before the 7 year period spoken of in Daniel often called the tribulation (think Left Behind). Presbyterians lean more to the Post-tribulation view or the Pre-Wrath view. There are overlaps though - some Baptists will hold to Post-Trib or Pre-Wrath, some Presbyterians will hold to the Pre-Trib rapture.
I hope this helps. God bless.
Raised Baptist, now Presbyterian