We think that both men and women wore a loincloth called a subligaculum or subligar. These were sometimes worn by men during manual labor and by upper-class men during exercise.
Women often wore a leather or cloth band to support the breasts called a strophium or mamillare.
For footwear as you mentioned, sandals were worn and for the most part the only distinction in status was in color, in which upper-class men often wore red sandals to denote their status as a patrician.
The tunic was the primary upper-body garment for men of all classes. Like sandals, class distinctions were noted with various colors and thicknesses of said colors.
The toga was a special upper-body clothing for Roman citizens, which like the Tunic and the sandals had many varieties that distinguished by both class and age. To quote from the VRoma Project, this list of differnent togae:
- toga virilis also called toga pura: unadorned toga in the off-white color of the undyed wool that was worn by adult male citizens
- toga praetexta: off-white toga with a broad purple border shown in the right-hand drawing. The only adults allowed to wear this toga were curule magistrates (curule aedile and above).
- toga pulla: toga made of dark-colored wool worn during periods of mourning
- toga candida: artificially whitened toga worn by candidates for political office
- toga picta: purple toga embroidered with gold thread worn by a victorious general during a triumphal parade and later adopted by emperors for state occasions. A variant of this costume was the toga purpura, an all-purple toga worn by the early kings and possibly adopted by some emperors
For jewlery, adult male citizens were only meant to wear a ring for the stamping of official documents, but many citizens ignored this social custom and instead wore the both this ring and other pieces of jewelry. Boys who were citizens often wore a smaller version of this in addition to their bulla.
Roman women would often where a peplos which would be two pieces of cloth sewn together that when buttoned at the shoulders would form a sleeveless dress.
A more common item of clothing was the chiton which was a sleeved tunic, which hung down to the ground and at sleeves which could be buttoned off at various points along the torso.
The pins and buttons described above were generally fibulae, which were simple and very similar to our modern safety pins. However, pins also came in very decorated varieties. Women also commonly wore rings and bracelets, in addition to necklaces which often were made with gold and inset pearls or other gems. Armbands were also popular.