It all heavily depends on how your specific college manages your curriculum and how open the choices are.
My personal example: decided to ignore most of the general studies classes I could ignore (aka those that weren't prereqs for any major-related classes, like most social studies) for the first year, did two 14-16 hour semesters for the first year, about 12 hours (each semester) for the second and third year (aka minimum required to be considered full time), took one fall semester off and then did one summer semester instead, and then finished off my last year with two back-to-back 22-24 hour semesters (during which I took a lot of those classes I ignored during my first year).
My school let us do it pretty much free-form, and it was amazing. Taking all the important major-related classes early on let me become knowledgeable enough for internships before a lot of peers (since I ended up taking some important major classes a semester or two ahead instead of taking gen ed classes like a lot of others did at the time), and during my last year I got a bit of a break by taking some of those "general ed" classes that most of my peers took early on.
I love this system, because it allows people to balance it all as they see fit. Some people would like to get all the gen ed classes out of the way first. Some would want to save them for last. Some would like to take them regularly at a "one general ed class per semester" pace. Some people would like to just do 16 credit hours every semester. Some would like to slow down at times and them ramp up heavily at times (which is what I did). Some would like to graduate early, others would like to take their time. Whichever style works for you.
And yeah, we had a general guideline for every major, with every class planned out every semester serving as a "sample workload", but it was just a guideline. Most people followed it to a degree, but not close. Others completely threw it out of the window, because they sorta knew what and how they wanted to do it. I think it is helpful to have for those who don't want to plan out things to their max efficiency and just want to not worry about it. But it isn't something that everyone is forced to abide by, it is more like an advice.
My personal example: decided to ignore most of the general studies classes I could ignore (aka those that weren't prereqs for any major-related classes, like most social studies) for the first year, did two 14-16 hour semesters for the first year, about 12 hours (each semester) for the second and third year (aka minimum required to be considered full time), took one fall semester off and then did one summer semester instead, and then finished off my last year with two back-to-back 22-24 hour semesters (during which I took a lot of those classes I ignored during my first year).
My school let us do it pretty much free-form, and it was amazing. Taking all the important major-related classes early on let me become knowledgeable enough for internships before a lot of peers (since I ended up taking some important major classes a semester or two ahead instead of taking gen ed classes like a lot of others did at the time), and during my last year I got a bit of a break by taking some of those "general ed" classes that most of my peers took early on.
I love this system, because it allows people to balance it all as they see fit. Some people would like to get all the gen ed classes out of the way first. Some would want to save them for last. Some would like to take them regularly at a "one general ed class per semester" pace. Some people would like to just do 16 credit hours every semester. Some would like to slow down at times and them ramp up heavily at times (which is what I did). Some would like to graduate early, others would like to take their time. Whichever style works for you.
And yeah, we had a general guideline for every major, with every class planned out every semester serving as a "sample workload", but it was just a guideline. Most people followed it to a degree, but not close. Others completely threw it out of the window, because they sorta knew what and how they wanted to do it. I think it is helpful to have for those who don't want to plan out things to their max efficiency and just want to not worry about it. But it isn't something that everyone is forced to abide by, it is more like an advice.