  Using data collected by the fixed target Fermilab experiment FOCUS, we
measure the branching ratios of the Cabibbo favored decays $\Xi_c^+ \to
\Sigma^+K^-\pi^+$, $\Xi_c^+ \to \Sigma^+ \bar{K}^{*}(892)^0$, and $\Xi_c^+ \to
\Lambda^0K^-\pi^+\pi^+$ relative to $\Xi_c^+ \to \Xi^-\pi^+\pi^+$ to be
$0.91\pm0.11\pm0.04$, $0.78\pm0.16\pm0.06$, and $0.28\pm0.06\pm0.06$,
respectively. We report the first observation of the Cabibbo suppressed decay
$\Xi_c^+ \to \Sigma^+K^+K^-$ and we measure the branching ratio relative to
$\Xi_c^+ \to \Sigma^+K^-\pi^+$ to be $0.16\pm0.06\pm0.01$. We also set 90%
confidence level upper limits for $\Xi_c^+ \to \Sigma^+ \phi$ and $\Xi_c^+ \to
\Xi^*(1690)^0(\Sigma^+ K^-) K^+$ relative to $\Xi_c^+ \to \Sigma^+K^-\pi^+$ to
be 0.12 and 0.05, respectively. We find an indication of the decays $\Xi_c^+
\to \Omega^-K^{+}\pi^+$ and $\Xi_c^+ \to \Sigma^{*}(1385)^+ \bar{K}^0$ and set
90% confidence level upper limits for the branching ratios with respect to
$\Xi_c^+ \to \Xi^-\pi^+\pi^+$ to be 0.12 and 1.72, respectively. Finally, we
determine the 90% C.L. upper limit for the resonant contribution $\Xi_c^+ \to
\Xi^{*}(1530)^0 \pi^+$ relative to $\Xi_c^+ \to \Xi^-\pi^+\pi^+$ to be 0.10.
