Proof of Besov space embeddings: $B_{p, \infty}^{s+\varepsilon}$ is continuously embedded in $B_{p, 1}^s$
After some thought, I came to the following proof. I hope firstly that it is correct and secondly that it may be able to help others. $$ \begin{align*} \|f\|_{B_{p,1}^s} &= \sum_{j \geq -1} 2^{js} \|\Delta_j f\|_{L^p} \\ &= \sum_{j \geq -1} 2^{-j(s+\varepsilon- s)} 2^{j(s+\varepsilon)} \|\Delta_j f\|_{L^p} \\ &= \sum_{j\geq -1} 2^{-j\varepsilon} 2^{j(s+\varepsilon)} \|\Delta_j f\|_{L^p} \\ &\leq \sum_{j\geq -1} 2^{-j\varepsilon} \sup_j 2^{j(s+\varepsilon)} \|\Delta_j f\|_{L^p} \\ &= \sum_{j\geq -1} 2^{-j\varepsilon} \|f\|_{B_{p, \infty}^{s+\varepsilon}} \\ &= C_{\varepsilon} \|f\|_{B_{p, \infty}^{s+\varepsilon}} \end{align*}.$$