• Systematic methods to analyze more complicated circuits
• Use differential equations to analyze transient response (ELEC 226)
• Analyze sinusoidal steady-state in the "frequency domain" using phasors and impedances
• Analyze circuits using Laplace transforms and the s-domain (ELEC 226)
• Analyze circuits with R, C, L, op amps, and mutual inductance (transformers)
• Three-phase circuits
• Two-port circuits
• PSpice for computer simulation and analysis
• More practice with the fundamental circuit analysis concepts so that you get good at them!!

In fact, even in graduate school, you study these same topics, but with increasing sophistication!